CBSE Class 8 Hindi Grammar मुहावरे और लोकोक्तियाँ Pdf free download is part of NCERT Solutions for Class 8 Hindi. Here we have given NCERT Class 8 Hindi Grammar मुहावरे और लोकोक्तियाँ.

CBSE Class 8 Hindi Grammar मुहावरे और लोकोक्तियाँ

भाषा को सुंदर और प्रभावशाली बनाने के लिए हम मुहावरों और लोकोक्तियों का प्रयोग करते हैं। इनके माध्यम से भाषा में कम-से कम शब्दों के प्रयोग से अधिक से अधिक भावों की अभिव्यक्ति की जा सकती है।

मुहावरा ऐसा शब्द-समूह या वाक्यांश होता है जो अपने शाब्दिक अर्थ को छोड़कर किसी विशेष अर्थ को प्रकट करता है। विशेष अर्थ में प्रयुक्त होने वाले ये वाक्यांश ही मुहावरे कहलाते हैं। जैसे नौ-दो ग्यारह होना मुहावरे का अर्थ है- भाग जाना।

लोकोक्ति यानी लोक की उक्ति अर्थात लोगों द्वारा कही गई उक्ति। ये अपने आप में पूर्ण वाक्य होती है। इनका प्रयोग अधिकांशतः वाक्य के अंत में एक स्वतंत्र वाक्य के रूप में होता है जबकि मुहावरों का प्रयोग वाक्य के मध्य में होता है।

मुहावरों में प्रयोग करते समय मुहावरों की क्रिया, लिंग, वचन, कारक आदि के अनुसार बदल जाती है।

1. अंग-अंग मुसकाना (बहुत प्रसन्न होना) – विद्यालय में प्रथम स्थान पाने पर आयुष का अंग-अंग मुसकरा रहा है।
2. अँगूठा दिखाना (साफ़ इंकार करना) – उसने कोमल से पुस्तक माँगी, लेकिन उसने अँगूठा दिखा दिया।
3. अंधे की लकड़ी (एकमात्र सहारा) – श्रवण कुमार अपने माता-पिता के लिए अंधे की लाठी था।
4. अगर-मगर करना (बहाने बनाना) – जब मैंने अपने मित्र से मुसीबत के समय सहायता माँगी तो वह अगर-मगर करने लगा।
5. आँखों में धूल झोंकना (धोखा देना) – सुभाष चंद्र बोस आँखों में धूल झोंककर भारत से गायब हो गए।
6. अक्ल पर पत्थर पड़ना (कुछ समझ में न आना) – आयुष आजकल ऐसे काम करता है, जिसे देखकर लगता है कि उसकी अक्ल पर पत्थर पड़ गया है।
7. अपने पाँव पर कुल्हाड़ी मारना (स्वयं अपना नुकसान करना) – सरकारी नौकरी छोड़कर अपनी दुकान खोलने की बात करना अपने पाँव पर कुल्हाड़ी मारने जैसा है।
8. आसमान सिर पर उठाना (बहुत शोर मचाना) – कक्षा में किसी अध्यापक के न होने के कारण छात्रों ने आसमान सिर पर उठा लिया।
9. आँखें फेर लेना (बदल जाना) – मुसीबत आने पर अपने भी आँखें फेर लेते हैं।
10. अपने मुँह मियाँ मिट्ठू बनना (अपनी प्रशंसा स्वयं करना) – अजय तुम कोई काम तो करते हो नहीं, बस अपने मुँह मियाँ मिठू बनते रहते हो।
11. आँखें चुराना (सामने आने से कतराना) – परीक्षा में कम अंक लाने के कारण पुत्र पिता से आँखें चुरा रहा है।
12. आँखें खुलना (होश आ जाना) – जब उसे अपने पुत्र की हरकतों का पता चला, तो उसकी आँखें खुल गईं।
13. आगा-पीछा करना (इधर-उधर होना) – प्राचार्य के मैदान में आते ही छात्र आगा-पीछा करने लगे।
14. आस्था हिलना (विश्वास उठना) – आजकल सच्चाई और ईमानदारी के प्रति लोगों की आस्था हिलने लगी है।
15. कान भरना (चुगली करना) – ज्ञान को कान भरने की बुरी आदत है।
16. कोई जोड़ न होना (मुकाबला न होना) – नेहा की लिखाई का कोई जोड़ नहीं है।
17. कातर ढंग से देखना (भय के भाव से नज़र बचाकर देखना) – बिना कारण पिटने पर ड्राइवर मुझे कातर भाव से देखने लगा।
18. कसर निकालना (कमी पूरी करना) – व्यापारियों ने त्योहारों के अवसर पर वस्तुओं को अत्यधिक दामों पर बेचकर कसर निकाल लेते हैं।
19. कमर तोड़ना (बहुत सुंदर लिखना) – अपने इस निबंध को लिखते हुए नेहा ने कमर तोड़ दिया है।
20. कान भरना (चुगली करना) – रजत हमेशा आयुष के खिलाफ अध्यापक के कान भरता रहता है।
21. कोल्हू का बैल (लगातार काम करना) – मैं यहाँ लगातार कोल्हू के बैल की तरह लगा रहता हूँ और तुम हो कि रात दिन मौज-मस्ती करते रहते हो।
22. कलई खुलना (भेद खुलना) – पड़ोसी के घर में रोज महँगे-महँगे समान आ रहे थे। अचानक एक दिन पुलिस के आने से उसकी सारी कलई खुल गई।
23. कानोकान खबर न होना (बिलकुल खबर न होना) – बदनामी के डर से मेहता जी कब दिल्ली छोड़कर चले गए, किसी को कानों कान खबर नहीं हुई।
24. खटाई में पड़ना (काम में अड़चन आना) – अच्छा खासा क्रिकेट खेल का आयोजन होने वाला था लेकिन बारिश के चलते सारा खेल का कार्यक्रम खटाई में पड़ गया।
25. खाक छानना (दर-दर भटकना) – नौकरी की तालाश में आजकल पढ़े-लिखे युवक दर-दर खाक छान रहे हैं।
26. गुड़गोबर होना (बात बिगड़ जाना) – अच्छा-खासा पिकनिक पर जाने का कार्यक्रम बना था लेकिन अचानक दंगा होने के कारण दिल्ली बंद ने सारा गुड़ गोबर कर दिया।
27. खाक में मिलाना (नष्ट-भ्रष्ट कर देना) – अमेरिका ने ईराक को खाक में मिला दिया।
28. घी के दिए जलाना (खुशियाँ मनाना) – बेटे के आई. ए. एस. बनने पर माँ-बाप ने घी के दिए जलाए।
29. घोड़े बेचकर सोना (गहरी नींद सोना) – बोर्ड परीक्षा सिर पर है और तुम घोड़े बेचकर सो रहे हो।
30. चिकना घड़ा (बेअसर/निर्लज्ज) – उसे कितना भी कुछ कह लो वह तो चिकना घड़ा है।
31. छक्के छुड़ाना (बुरी तरह हरा देना) – भारतीय सैनिकों ने युद्ध में पाकिस्तानी सैनिकों के छक्के छुड़ा दिए।
32. छठी का दूध याद आना (कठिनाई का अनुभव होना) – बिना परिश्रम के परीक्षा में बैठने से आयुष को छठी का दूध याद आ गया।
33. छाती पर मूंग दलना (बहुत तंग करना) – मोहनलाल के मेहमान साल भर उसकी छाती पर मूंग दलते रहते हैं।
34. टका-सा जवाब देना (साफ़ मना कर देना) – मैंने जब हरि प्रसाद से मुसीबत के समय उधार पैसे मांगे तो उसने टका-सा जवाब दे दिया।
35. दाल में काला होना (कुछ गड़बड़ होना) – उसके घर पुलिस आई है, लगता है दाल में कुछ काला है।
36. नौ-दो ग्यारह होना (भाग जाना) – चोर किमती सामान उड़ाकर नौ-दो ग्यारह हो गया।
37. दिन दूनी रात चौगुनी उन्नति करना (अधिकाधिक उन्नति) –  ईश्वर करे, तुम दिन दूनी, रात चौगुनी उन्नति करो।
38. तूती बोलना (बहुत प्रभाव होना) – रमेश बाबू के समाज-सेवी होने की तूती सारे शहर में बोल रही है।
39. नाक में दम करना (बहुत परेशान करना) – आजकल उग्रवादियों ने देश में नाक में दम कर रखा है।
40. नाको चने चबाना (बहुत कठिन कार्य करना) – सुबह से लेकर शाम तक इन बच्चों की देखभाल करना तो नाको चने चबाने के बराबर है।
41. पहाड़ टूटना (भारी संकट आ जाना) – पिता की आकस्मिक मृत्यु से गोपाल पर तो मानों पहाड़ ही टूट पड़ा है।
42. पर निकलना (स्वच्छंद हो जाना) – कॉलेज में दाखिला लेते ही नेहा के पर निकलने लगे।
43. पगड़ी उछालना (अपमानित करना) – बुजुर्गों की पगड़ी उछालना अच्छी बात नहीं है।
44. पानी-पानी होना (अत्यंत लज्जित होना) – मिलावट खोरी करते हुए रंगे हाथ पकड़े जाने पर रजत पानी-पानी हो गया।
45. फूला न समाना (बहुत प्रसन्न होना) – जब से नेहा का नाम मेडिकल कॉलेज की प्रवेश सूची में आया है, वह फूले नहीं समा रही है।
46. हवा से बातें करना (बहुत तेज दौड़ना) – बुलेट ट्रेन हवा से बातें करती है।
47. हाथ साफ़ करना (चुरा लेना) – जेब कतरा कुछ यात्रियों की जेब पर हाथ साफ़ करके चपंत हो गया।
48. राई का पहाड़ बनाना (जरा-सी बात को बढ़ा-चढ़ाकर कहना) – तुम राई का पहाड़ न बनाते तो यह संकट खड़ी न होती।
49. लाल-पीला होना (गुस्से में होना) – आप तो बिना वजह मुझ पर लाल-पीला हो रहे हैं।
50. लाल-पीला होना (क्रोध करना) – वार्षिक परीक्षा में पुत्र के फेल होने से पिता जी लाल-पीले होने लगे।
51. लोहे के चने चबाना (कठिन काम करना) – आई. ए. एस. परीक्षा में सफलता प्राप्त करना लोहे के चने चबाना है।
52. थाली का बैगन (अस्थिर व्यक्ति) – अधिकतर नेता थाली के बैगन होते हैं।
53. हवाई किले बनाना (कल्पनाएँ करना) – आजकल नेता हवाई किले बनाते हैं।
54. हाथ मलना (पछताना) – अवसर का फायदा उठाने में ही समझदारी है वाद में हाथ मलते रह जाओगे।
55. सिर चकराना (घबरा जाना) – सी०बी०एस०ई० बोर्ड का प्रश्न पत्र देखकर छात्रों का सिर चकरा गया।
56. सिर धुनना (पछताना) – छात्र अपना खराब परीक्षा परिणाम देखकर अपना सिर धुनने लगा।
57. सिर उठाना (बगावत करना) – महँगाई पर अंकुश लगाने में असफल होने पर अपनी ही पार्टी के कई सांसदों ने सिर उठाना शुरू कर दिया।
58. हाथ मलना (पछताना) – अभी समय रहते परिश्रम कर लो, नहीं तो बाद में पछताना पड़ेगा।
59. हक्का बक्का रह जाना (हैरान रह जाना) – फल बेचने वाला अपने खाते में 10 करोड़ रुपए देखकर हक्का-बक्का रह गया।
60. हवा हो जाना (भाग जाना) – शेर को देखते ही सारे जानवर हवा हो गए।

बहुविकल्पी प्रश्न

नीचे दिए गए मुहावरों के उचित अर्थ पर सही का चिह्न लगाओ।

1. “अँगूठा दिखाना’ का अर्थ है
(i) डराना
(ii) मज़ाक उड़ाना
(iii) इशारा करना
(iv) साफ़ इंकार करना

2. ‘आँखें दिखाना’ का अर्थ है
(i) इशारा करना
(ii) डराना
(iii) क्रोध करना
(iv) अपनी बात कहना

3. ‘रंग उड़ना’ का अर्थ है
(i) उड़कर जाना
(ii) रंग चला जाना
(iii) भाग जाना
(iv) चेहरा फीका पड़ना

4. ‘चिकना घड़ा होना’ का अर्थ है–
(i) चिकने घड़े को सभी पसंद करते हैं।
(ii) अत्यंत आकर्षक होना
(iii) निर्लज्ज होना
(iv) चिकना बनाने के लिए घड़े पर तेल लगाना

5. दाल में काला होना
(i) दाल में मिलावट होना
(ii) संदेह होना
(iii) दाल में मक्खी गिरना
(iv) काली छिलके वाली दाल बनाना

6. ‘ठेस लगना’ का अर्थ है?
(i) ठोकर लगना
(ii) सदमा पहुँचना
(iii) ठोस जवाब
(iv) ठोकर मारना

उत्तर-
1. (iv)
2. (ii)
3. (iv)
4. (iii)
5. (ii)
6. (ii)

लोकोक्तियाँ

1. अधजल गगरी छलकत जाए (कम जानने वाला व्यक्ति अधिक दिखावा करता है।) – समीर को चपरासी की सरकारी नौकरी क्या मिल गई, पूरे गाँव में किसी से सीधे मुँह बात नहीं करता। इसे कहते हैं – अधजल गगरी छलकत जाए।
2. आम के आम गुठलियों के दाम (दोहरा लाभ) – मैं परीक्षा देने दिल्ली जा रही हूँ। लाल-किला और इंडिया गेट देख लँगी। इसे कहते हैं आम के आम गुठलियों के दाम।
3. अंधों में काना राजा (मूर्खा में थोड़ा जानने वाला व्यक्ति भी आदर पा जाता है।) – पूरे गाँव में मदनलाल,ही आठवीं पास है। गाँव वाले उसे विद्वान समझकर उसका आदर करते हैं। इसी को कहते हैं अंधों में काना राजा।।
4. अकेला चना भाड़ नहीं फोड़ सकता (अकेला आदमी कुछ नहीं कर सकता) – सामाजिक बुराईयों से लड़ने के लिए हमें सबको एक साथ होकर लड़ाई लड़नी होगी। आपने सुना ही होगा कि अकेला चना भाड़ नहीं फोड़ सकता।
5. अपना हाथ जगन्नाथ (परिश्रम से ही सफलता मिलती है।) – दूसरों की कृपा पर जिंदा रहने से तो अच्छा है, परिश्रम करके खाओ, क्योंकि अपना हाथ जगन्नाथ।
6. उलटा चोर कोतवाल को डाँटे-(अपराध करने वाला उलटी धौंस जमाए) – बबीत ने मेरा कॉपी चुरा लिया। उससे पूछा तो लड़ने लगा। इसी को कहते हैं – उलटा चोर कोतवाल को डाँटे।।
7. एक अनार सौ बीमार-(एक वस्तु के अनेक चाहने वाले) – नौकरी में पाँच पद के लिए पचास हजार आवेदन पत्र देखकर एक अनार सौ बीमार वाली कहावत चरितार्थ होती है।
8. खोदा पहाड़ निकली चुहिया-(अधिक परिश्रम करने पर कम लाभ) – पूरे वर्ष कठिन परिश्रम करने के बाद जब मंथन कक्षा में 25 प्रतिशत अंक ला पाया, तो उसके मुँह से यही निकला खोदा पहाड़, निकली चुहिया।
9. ऊँची दुकान फीके पकवान-प्रसिद्धि के अनुरूप गुणों का न होना – हमने तो इस दुकान का नाम सुनकर इससे सामान खरीदा था, पर वह बहुत ही घटिया निकला। इसे कहते हैं ऊँची दुकान फीके पकवान।
10. दूध का दूध पानी का पानी (स्पष्ट न्याय करना) – राजा विक्रमादित्य दूध का दूध और पानी का पानी कर दिया करते थे।
11. नाच न जाने आँगन टेढ़ा (खुद काम न आने पर दूसरों को दोष देना) – गाना तो उससे ठीक से गाया नहीं गया और दोष देने लगा तबला बजाने वाले को। इसे कहते हैं नाच न जाने आँगन टेढ़ा।
12. जैसी करनी वैसी भरनी-(कार्य के अनुसार फल की प्राप्ति) शिवम ने दिन-रात परिश्रम किया, वह प्रथम आया। लेकिन आयुष ने वर्ष भर खूब मौज उड़ाई, वह अनुत्तीर्ण हो गया। किसी ने ठीक कहा है – जैसी करनी वैसी भरनी।
13. साँच को आँच नहीं ( सच्चे को डरने की आवश्यकता नहीं) – जब तुमने चोरी की ही नहीं, तो डरते क्यों हो? जानते नहीं साँच को आँच नहीं आती।
14. चमड़ी जाए पर दमड़ी न जाए (बहुत कंजूस होना) – मदनलाल एक सप्ताह से बीमार है, पर खर्चे के कारण डॉक्टर को नहीं बुलाना चाहता। उसके लिए तो चमड़ी जाए पर दमड़ी न जाए वाली बात लागू होती है।
15. भागते चोर की लंगोटी भली (सब कुछ बर्बाद होता देख, कुछ बचा लेना अच्छा है) – किरायेदार पाँच महीने का किराया दिए बिना ही भाग गया, मगर गिरवी पड़े जेवर छोड़ गया मैंने सोचा-भागने चोर की लंगोटी भली।

We hope the given CBSE Class 8 Hindi Grammar मुहावरे और लोकोक्तियाँ will help you. If you have any query regarding CBSE Class 8 Hindi Grammar मुहावरे और लोकोक्तियाँ, drop a comment below and we will get back to you at the earliest.

The post CBSE Class 8 Hindi Grammar मुहावरे और लोकोक्तियाँ appeared first on Learn CBSE.

CBSE Class 8 English Grammar Determiners are part of NCERT Solutions for Class 8 English. Here we have given CBSE Class 8 English Grammar Determiners.

CBSE Class 8 English Grammar Determiners

Note : Articles and possessive adjectives together are called determiners. Here, in this first chapter, we are dealing with articles only. The possessive adjective can be studied in chapter number 3.
Three words—a, an and the are called articles. They are divided in two groups.

A. The Definite Article (The)
1. Use of Definite Article
(a) Put the before the words which mean the inhabitants of a country.
The English live in England and the Indians in India.
But do not put the before the names of the language.
English is spoken in England and Hindi in India.
Exception
Plural nouns of a country’s inhabitants do not take the if they are thought of individually.
Indians are generally vegetarians.
Russians drink vodka.

(b) Put the before the names of mountain ranges.
The Alps, the Himalayas
But do not put the before the names of single mountains or hills.
Everest, Mont Blanc (not the Everest, the Mont Blanc)

(c) Use the before the names of rivers, canals, seas, oceans, valleys, deserts and forests :
Lucknow is on the Gomati. (not on Gomati)
Similarly we say—
The North Sea, The Indian Ocean, The Ganges, The Sahara.

(d) Use the before the names of ships and trains :
The Rajdhani Express runs fast.
The Titanic was a very big ship.
But do not use the before the vehicles when they indicate a means of transport :
I will go to Delhi by bus.
We are going to Mumbai by train.

2. Omission of the Definite Article
(a) Do not put the before the names of substances if they are used in a general sense.
Gold is a precious metal. (not the gold)
Bread is made from flour. (not the bread … the flour)
Lead is very heavy. (not the lead)
But the must be used if the reference is to a particular kind or type.
The thieves stole the gold from that ship.
The bread in this hotel is of poor quality.

(b) Do not put the before the names of meals if they refer to the meals generally.
When do you have dinner ?
Have you had breakfast ?
Lunch is at 2.00 p.m.
But use the when the meal is a particular one.
The dinner will be taken at Ashoka.
We enjoyed the lunch given by the school.

(c) Do not use the before plural nouns when they are used in a general sense.
Books are necessary for students.
Apples grow in Simla.
Cars can run fast.

(d) Do not use the before the names of games.
Sania Mirza plays Tennis.
Chess is a game which requires skill.

(e) Do not put the before the names of the countries unless the name denotes that it is made of parts.
India, Italy, France and China are all republics.
But
The United States is very rich.
The U.S.S.R. has broken into smaller units.

(f) Do not use the before the names of the offices if these follow the names of the officers :
Prime Minister Dr. Manmohan Singh President Dr. Abdul Kalam D.C. Miss. Rajni Kothari
But if the names are not mentioned the must be used.
The Prime Minister. The President etc.

Exercise 1
(Solved)

Fill in the blanks with the where necessary.
1. The table was made of …….. wood.
2. ……… water in that pot is not fit for drinking.
3. ………. sweets we took after meals were tasty.
4. When do you have ………. breakfast?
5. Are you attending ………. dinner tonight?
6. Why do we wear ……. clothes?
Answers:
1. x (No article)
2. The
3. The
4. x (No article)
5. the
6. x (No article).

B. The Indefinite Article (A and An)
(a) A is used before words beginning with a consonant, and an before words begin¬ning with a vowel or with a letter h which is not sounded. The following are the main words which are spelt with unsounded h.

(b) If a word begins with a vowel but is pronounced in the way as ‘y’ in yet, write a and not an before it.
a university, a European.

(c) A/an is to be used only before singular countable nouns.
a book, a city, an animal.
A/an should be used before the adjective if these singular countable nouns have an adjective before them.
a big city, a fine book, an ignorant person.

(d) Use a after the word such when it is applied to things which are countable.
I have never known such a cold winter.
Such a thing has never happened before.

(e) If instead of such, there is the word so, then put a after the adjective, just before the noun.
I have never known so cold a winter. (not a so cold winter)

(f) When a is placed before the word few. it changes the meaning. Few means a small number when more might have been expected ; a few means a small number when none were expected.
Few boys were present in the class. (i.e., I had expected more)
A few boys were present in the class.
(i.e, I had expected none, still there was a small number of them present) There is a similar difference between little and a little.
We have little time to spare.
(It means that we do not have as much time as we should like).
We have a little time to spare.
(It means that we are not so short of time that we cannot spare any).

Exercise 2
(Solved)

Fill in the blanks with a or an.
1. ………. man and ………….. woman were sitting before me.
2. During our holiday, we stayed at ………… hotel.
3. For our dinner, we went to …………. restaurant.
4. As it was raining, I took …………. umbrella.
5. On the way, I saw …………. elephant.
6. I am ……………… Indian whereas you are Chinese.
Answers:
1. A, a
2. a
3. a
4. an
5. an
6. an. a

Exercise 3
(Solved)

Fill in the blanks with a or an.
1. Have you ever seen ………… lion?
2. Does Sohan have a ……….. car ?
3. Is there ……………. bank nearby?
4. There isn’t ………….. airport nearby.
5. Ram is …………… honest man.
6. He will return in ……….. hour.
Answers:
1.a
2. a
3. a
4. an
5. an
6. an

Exercise 4
(Solved)

Insert a, an or the.
Once there was (1) ……. mouse. The mouse was always afraid of (2) ……… cat. A magician took pity on (3) ……… mouse. He turned it into (4) ……… cat. Now (5) ……… cat was afraid of dogs. So, (6) ……… magician turned (7) ……… cat into (8) ……….. dog and finally into (9) …….. tiger. (10) …… tiger began to fear hunters in (11) ……. forest. Then (12) ……… magician said, “Be (13) ………. mouse again. You are no better than (14) …… mouse at heart”.
Answers:
1. a
2. the
3. the
4. a
5. the
6. the
7. the
8. a
9. a
10. The
11. the
12. the
13. a
14. a

Exercise 5
(Solved)

Fill In the blanks with few, little, a few, a little, the few, the little.
1. Just …………… persons were present there.
2. I cannot prepare tea; there is …………. milk in the house.
3. I have consumed ………… sugar you gave me.
4. ………… water of the pond will not last the year.
5. The class was not held as …………. students were present.
6. Don’t worry. I have ………… money in the bank.
Answers:
1. a few
2. little
3. the little
4. The little
5. few
6. a little

Exercise 6
(Solved)

Rearrange the following words / phrases so as to make meaningful sentences.
1. it is easy / acquire / bad habit / to / a / very difficult / to live / bad person / with the / has it / who / but
2. I / never / a / known / have / such / bad time
3. coffee / let’s go / restaurant / into / have / the / and
4. dog / faithful animal / is / the / a
5. few pupils / right answer / only / gave / a / the.
Answers:
1. It is easy to acquire a bad habit but very difficult to live with the bad person who has it.
2. I have never known such a bad time.
3. Let’s go into the restaurant and have coffee.
4. The dog is a faithful animal.
5. Only a few pupils gave the right answers.

Exercise 7
(Solved)

In the passage given below, one word has been omitted in each line. Write the missing word along with the word that comes before and the word that comes after it in your answer sheet. Ensure that the word that forms your answer is underlined.

Answers:
(a) was a poor
(b) for a famous
(c) was a tall
(d) to a rich
(e) at the party
(f) on the occasion

Exercise 8
(Solved)

In the passage given below, one word has been omitted in each line. Write the missing word along with the word that comes before and the word that comes after it in your answer sheet. Ensure that the word that forms your answer is underlined.

Answers:
(a) see the National
(b) bought a few
(c) was a story
(d) read a story
(e) all the stories

Exercise 9
(Solved)

The following passage has not been edited. There is one error in each of the lines. Write the incorrect word and the correction in your answer book.
Answers:
(a) a — the
(b) an — a
(c) the — an
(d) a — the
(e) the few — a few

Use of ‘Enough ’
1. As determiner :
Used before plural or uncountable nouns, it means ‘as many or ‘as much’ as some¬body needs or wants i.e., sufficient.
Have you made enough copies ?
There is enough room for everybody.
I have enough clothes to last a week.
I have enough problems as it is.

2. As a pronoun :
If enough of you are interested, we shall go there.
Six bottles should be enough.
There was nowhere near enough for everybody.

3. As an adverb :
This house is big enough for us.
She is not old enough to decide for herself.
We didn’t start early enough.
It is not just good enough.
He seemed good enough to me.
Life is hard enough as it is.

Exercise 10
(For Practice)

Fill in the blanks with the where necessary.
1. Some soaps are made of ……….. oils and some of only ………. chemicals.
2 …….. iron is found in India.
3. In India more people drink …………. milk than …… wine.
4. ………….  mangoes are grown in India, Pakistan and Sri Lanka.
5. Will you play ………….. cricket ?
6. She plays ……………. basketball very well.

Exercise 11
(For Practice)

Complete the following passage by filling the blanks :
There was (a) ………… accident near (b) ………….. market, (c) …………. car hit (d) ……….. bicycle and (e) ………… man on (f) ……….. bicycle was killed on (g) ………. spot.

Exercise 12
(For Practice)

The following passage has not been edited. There is one error in each of the lines. Write the incorrect word and the correction in your answer book.

Multiple Choice Questions

The underlined words in the following passages have not been used appropriately. Replace them by choosing the most appropriate option from the ones given below the passage.
Question 1.
Have you seen (a) some elephant ? This is (b) a largest living animal on earth. It has played (c) the very important role in our economy. Over (d) a past 40 million years, more than 600 species of (e) some elephant have roamed (f) a earth.
(a)
(i) a
(ii) an
(iii) few
(iv) little

(b)
(i) the
(ii) an
(iii) few
(iv) little

(c)
(i) many
(ii) an
(iii) little
(iv) some

(d)
(i) many
(ii) an
(iii) the
(iv) few

(e)
(i) the
(ii) an
(iii) a
(iv) little

(f)
(i) some
(ii) the
(iii) an
(iv) little

Question 2.
Smoking is (a) a single largest preventable cause of death all over (b) an world. This is (c) a alarming fact. In spite of this (d) much and more people are taking to smok¬ing in India. According to (e) an studies, India. Indonesia and China are (f) a only countries where the incidence of smoking is going up.
(a)
(i) the
(ii) an
(iii) some
(iv) few

(b)
(i) some
(ii) a
(iii) the
(iv) more

(c)
(i) a
(ii) an
(iii) the
(iv) more

(d)
(i) a
(ii) some
(iii) more
(iv) few

(e)
(i) the
(ii) an
(iii) some
(iv) few

(j)
(i) an
(ii) few
(iii) some
(iv) the

Question 3.
What starts as (a) a experiment, soon turns into (b) an habit. There is (c) a nicotine in cigarettes which brings structural changes in (d) a brain. Smoking has (e) a associational aspect as well. People smoke while reading or with (f) an cup of tea.
(a)
(i) an
(ii) the
(iii) some
(iv) few

(b)
(i) the
(ii) a
(iii) some
(iv) few

(c)
(i) the
(ii) a
(iii) some
(iv) few

(d)
(i) some
(ii) an
(iii) a
(iv) the

(e)
(i) an
(ii) some
(iii) few
(iv) many

(f)
(i) the
(ii) a
(iii) some
(iv) many

Question 4.
(a) Some Mohwa tree has (b) an large grey bark. Most of (c) an leaves fall from February to April. During that time (d) a scented flowers hang in close branches of (e) some dozen or so. At dawn (f) a short-lived flower falls.
(a)
(i) The
(ii) An
(iii) Some
(iv) Few

(b)
(i) the
(ii) a
(iii) some
(iv) few

(c)
(i) a
(ii) an
(iii) the
(iv) som

(d)
(i) some
(ii) an
(iii) each
(iv) the

(e)
(i) some
(ii) a
(iii) the
(iv) each

(j)
(i) an
(ii) the
(iii) some
(iv) each

Question 5.
(a) A plaving of games is (b) some worthy activity. It is worthy in the sense that (c) an team spirit can be created in (d) a individual only if he has learnt to participate in (e) a playing of games. It is also true that a player does (f) more for the society.
(a)
(i) An
(ii) The
(iii) Some
(iv) Much

(b)
(i) more
(ii) any
(iii) much
(iv) a

(c)
(i) little
(ii) a
(iii) few
(iv) much

(d)
(i) an
(ii) little
(iii) some
(iv) much

(e)
(i) much
(ii) any
(iii) the
(iv) an

(f)
(i) the
(ii) an
(iii) a
(iv) much

Question 6.
Nobody knows exactly where (a) a orange originated. Today it is grown in most of (b) an warmer parts of the world, (c) a orange a day can give you (d) some sufficient supply of vitamin C. In India (e) a orange grown in Nagpur is famous for its quality. (f) a orange juice is a famous drink loved by Indians.
(a)
(i) an
(ii) the
(iii) some
(iv) few

(b)
(i) a
(ii) the
(iii) some
(iv) few

(c)
(i) The
(ii) Some
(iii) An
(iv) Few

(d)
(i) a
(ii) an
(iii) few
(iv) the

(e)
(i) an
(ii) some
(iii) the
(iv) few

(f)
(i) Some
(ii) An
(iii) A
(iv) The

Question 7.
(a) A great wall of China is said to be one of (b) an structures which would be visible from (c) an moon. There are (d) a little things which are considered to be (e) an wonders of the world . This wall is i one of them. (f) A man who did most to build it was General Meng Tien.
(a)
(i) The
(ii) An
(iii) A few
(iv) Some

(b)
(i) a
(ii) the
(iii) the few
(iv) little

(c)
(i) a
(ii) the
(iii) few
(iv) little

(d)
(i) a
(ii) few
(iii) little
(iv) a few

(e)
(i) a
(ii) the
(iii) some
(iv) little

(f)
(i) Some
(ii) The
(iii) An
(iv) few

Answers
1.
(a) an
(b) the
(c) some
(d) the
(e) the
(f) the

2.
(a) the
(b) the
(c) an
(d) more
(e) some
(f) the

3.
(a) an
(b) a
(c) some
(d) the
(e) an
(f) a

4.
(a) The
(b) a
(c) the
(d) the
(e) a
(f) each.

5.
(a) The
(b) a
(c) a
(d) an
(e) the
(f) much

6.
(a) the
(b) the
(c) An
(d) a
(e) the
(f) The

7.
(a) The
(b) the
(c) the
(d) a few
(e) the
(f) the

We hope the CBSE Class 8 English Grammar Determiners help you. If you have any query regarding CBSE Class 8 English Grammar Determiners, drop a comment below and we will get back to you at the earliest.

The post CBSE Class 8 English Grammar Determiners appeared first on Learn CBSE.

CBSE Class 8 English Grammar Nouns are part of NCERT Solutions for Class 8 English. Here we have given CBSE Class 8 English Grammar Nouns.

CBSE Class 8 English Grammar Nouns

Definition. Noun is the name given to a thing, person, object (animate or inani¬mate) or feeling : e.g.,
Ram, man, dog, book, tree, light, love etc.
Kinds of Noun :
Noun can be of two kinds :
A. Countable nouns like book, man etc.
B. Uncountable nouns like light, bread etc.
(a) An uncountable noun is sometimes used as countable noun.
Three teas, please.
Here ‘three teas’ means three cups of tea.
There were dozens of ice-creams.
It means there were dozens of kinds of ice-cream.
Compare :
She has curly hair.
There is a hair in my soup.

(b) Some nouns have different meanings when they are used countably and when used uncountably.
Glass is fragile.
Give me a glass of water.
This is a three-room-house.
There is no room for dishonesty in this company.

(c) Collective nouns such as a group, a crowd, a herd, a team etc are singular. However, if we think of the members individually, a plural verb may be used. Compare :
A flock of sheep was grazing.
A flock of sheep were straying all over the road causing confusion in the traffic.
In the first sentence the speaker is thinking of the sheep as a group.
In the second sentence, he has different sheep—some straying in one direction and some in the other. So we use a plural verb there.

(d) Some nouns have a plural form but are always treated as singular.
What is the latest news ?

Exercise 1
(Solved)

Fill in the blanks using the proper forms of the nouns i.e., singular or plural. The noun for each sentence is given in a bracket at its end.
1. All the ……… has been consumed. (sugar)
2. The ………….. is expected to arrive today, (team)
3. Good ………… is expensive. (cutlery)
4. A lot of ………. was drunk. (milk)
5. The ………. has now been spent. (money)
Answers:
1. sugar
2. team
3. cutlery
4. milk
5. money

Exercise 2
(Solved)

Choose the correct forms of the nouns given in the brackets.
1. A large ………. is expected. (crowd/crowds)
2. This pair of ………. is good. (shoe/shoes)
3. These ……… were found there, (glove/gloves)
4. Many ……….. have visited us. (people/peoples)
5. Most ………. are well-built. (house/houses)
8. The ……….. need sharpening, (scissor/scissors)
Answers:
1. crowd
2. shoes
3. gloves
4. people
5. houses
6. scissors

Exercise 3
(Solved)

Rearrange the following words / phrases so as to make meaningful sentences.
1. all / have been eaten / mangoes / the
2. school / rooms / our / forty / has
3. cricket ball / leather / a / made of / is
4. Italy / a young boy / to / art / study / went to
5. the boy / did / was / everything / very clever
6. that boy / in Florence / grew up / to be / painter / the greatest
Answers:
1. All the mangoes have been eaten.
2. Our school has forty rooms.
3. A cricket ball is made of leather.
4. A young boy went to Italy to study art.
5. Everything the boy did was veiy clever.
6. That boy grew up to be the greatest painter in Florence.

Exercise 4
(Solved)

The following passage has not been edited. There is a mistake in each line. Write the incorrect word as well as the correction in your answer sheet :

Answers:
(a) men — man
(b) peoples — people
(c) churches — church
(d) plants — plant
(e) everythings — everything
(f) drawing — drawings

Exercise 5
(Solved)

Complete the sentences given below taking one word each to fill in a gap from the given box.

1. John gave a present to his……..
2. Children must respect their ……
3. ………. is good.
4. ……… are good.
5. His ……… are weak.
6. His ………. is weak.
Answers:
1. mother
2. mothers
3. News
4. People
5. shoes
6. physics

Exercise 6
(Solved)

Correct the following sentences:
1. Where is your luggage ?
2. What a beautiful scenery !
3. Can you give me a piece of advice ?
4. have an important piece of work to do.
5. He has eaten two pieces of bread.
6. What awful weather !
Answers:
1. Where is your luggage ?
2. What a beautiful scenery !
3. Can you give me a piece of advice ?
4.1 have an important piece of work to do.
5. He has eaten two pieces of bread.
6. What awful weather !

Exercise 7
(For Practice)

Fill in the blanks choosing either of the words given in the brackets after each sentence :
1. A group of ……… was standing there.(people/peoples)
2. The ……… is to be delivered.(furniture/furnitures)
3. The …….. belong to me. (scissor/scissors)
4. The ………. were grazing. (cattle/cattles)
5. ………. swim in water. (Fish/Fishes)
6. He gave me much ………. (advice/advices)

Exercise 8
(For Practice)

Correct the following sentences :
1. A flock of sheep were grazing in the field.
2. His trouser were tom.
3. A pair of shoe was standing there.
4. A lot of works have still to be done.
5. There are plenty of rooms on the back row.
6. What are the latest news ?

Multiple Choice Questions
Exercise 1

Choose the correct word from the brackets to complete the sentences :
1. She has blonde ………. (hair/hairs/a hair/many hairs).
2. The statue is made of ……….. (stone/a stone/stones/few stones).
3. A large ……….. (crowd/crowds/people/peoples) is expected there.
4. This pair of …………. (shoe/shoes/boot/leatger) is good.
5. Most ……… (house/building/houses/mansion) are made of brick.
Answers:
1. hair
2. stone
3. crowd
4. shoes
5. houses

Exercise 2

The underlined words in each sentence have been wrongly used. One of the words in the brackets is the correct option. Choose that word :
Question 1.
Where had vour luggage ?
(a) are
(b) were
(c) is
(d) has

Question 2.
There has a flock of sheep.
(a) is
(b) are
(c) were
(d) had

Question 3.
No news seem good news,
(a) are
(b) were
(c) is
(d) has

Question 4.
There has plenty of mangoes in the house.
(a) is
(b) are
(c) was
(d) had

Question 5.
Common people election the government.
(a) elect
(b) elects
(c) electioned
(d) elections

Answers:
1. (c) is
2. (a) is
3. (c) is
4. (b) are
5. (a) elect

We hope the CBSE Class 8 English Grammar Nouns help you. If you have any query regarding CBSE Class 8 English Grammar Nouns, drop a comment below and we will get back to you at the earliest.

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CBSE Class 8 English Grammar Noun Phrase are part of NCERT Solutions for Class 8 English. Here we have given CBSE Class 8 English Grammar Noun Phrase.

CBSE Class 8 English Grammar Noun Phrase

1. Read the following sentences :

1. I want something
2. I want to read a book.

The word something is a noun and is object of the verb ‘want’, in sentence (i). In the same way, the group of words ‘to read a book’ is the object of the verb ‘want’ in sentence (if). The group of words ‘to read a book’, therefore does the work of a noun and is called a ‘Noun Phrase’.
Def. : A Noun Phrase is a group of words which does the work of a noun.

Exercise 1
(Solved)

Pick out the noun phrases in the following sentences:
1. I wished to speak to the Principal.
2. He loves to talk to you.
3. I intend to work hard.
4. He dislikes having to go there.
5. Horses prefer living in a dark room.
6. I should hate having to punish him.
7. Have you ever tried using butter instead of oil ?
8. Thinking good thoughts precedes good actions.
9. He refuses to write anything.
10. Having dirty thoughts is disgraceful.
Answers:
1. to speak to the Principal
2. to talk to you
3. to work hard
4. having to go there
5. living in a dark room
6. having to punish him
7. using butter instead of oil
8. Thinking good thoughts
9. to write anything
10. Having dirty thoughts.

Exercise 2
(For Practice)

Supply a Noun Phrase:
1. I want ……..
2. ……… delights me.
3. You expect ………
4. Think ……
5. ……. seems true.
6. ………. surprised the teacher.
7. Does he like …….. ?
8. My brother hates ………..
9. ……… does not please me.
10. I do not want ………
11. ………. is not difficult.
12. ……. I do not hope
13. I enjoy …….
14. You want ……..
15. My dog likes ………
16. He promised ……..

Multiple Choice Questions

Read the following groups of sentences carefully. Only one in each group has a noun phrase. Pick that sentence which has the Noun Phrase :
Question 1.
(a) Use the space around you
(b) He has left for Delhi
(c) I did not meet him
(d) What do you want ?

Question 2.
(a) Do not waste time
(b) He did what he was told
(c) Is your bank making money ?
(d) Loans are available here

Question 3.
(a) He waited, hands clasped, relaxed
(b) Suddenly he burst through the door
(c) He has taken his seat
(d) She ran to school

Question 4.
(a) He is getting married
(b) His brother lives close by and helps him
(c) I have arrived late
(d) To err is human.

Question 5.
(a) I have learnt from you how to love
(b) You cannot learn quickly
(c) What do you want from me
(d) He is too old to walk properly

Question 6.
(a) The plane took off at four O’clock
(b) I want you to come
(c) You needn’t work so hard
(d) The boys broke into laughter

Question 7.
(a) The sun rises in the east
(b) Humpy Dumpy sat on a wall
(c) It was a sunset of great beauty
(d) Show me how to do it

Question 8.
(a) The mountain top was covered
(b) He has a chain of gold with snow
(c) The house is full
(d) He is not likely to recover

Answers:
1. (a) Use the space around you
2. (b) He did what he was told
3. (c) He has taken his seat
4. (d) To err is human
5. (a) I have learnt from you how to love
6. (b) I want you to come
7. (d) Show me how to do it
8. (b) He has a chain of gold

We hope the CBSE Class 8 English Grammar Noun Phrase help you. If you have any query regarding CBSE Class 8 English Grammar Noun Phrase, drop a comment below and we will get back to you at the earliest.

The post CBSE Class 8 English Grammar Noun Phrase appeared first on Learn CBSE.

CBSE Class 8 Hindi Grammar शब्द-भंडार Pdf free download is part of NCERT Solutions for Class 8 Hindi. Here we have given NCERT Class 8 Hindi Grammar शब्द-भंडार.

CBSE Class 8 Hindi Grammar शब्द-भंडार

वर्गों के सार्थक समूह को शब्द कहते हैं। शब्द और अर्थ का अत्यंत घनिष्ठ संबंध है। एक तरह से शब्द का बोध उसके अर्थ से है। अर्थ भी एक तरह का शब्द ही है। अर्थ के आधार पर शब्दों को निम्नलिखित वर्गों में बाँटा जाता है

• पर्यायवाची या समानार्थी शब्द
• विलोम शब्द
• अनेकार्थी शब्द
• समरूपी भिन्नार्थक शब्द
• एकार्थी शब्द
• अनेक शब्दों के लिए एक शब्द
• समान अर्थ प्रतीत होने वाले शब्द।।

1. पर्यायवाची शब्द – वे शब्द जो अर्थ की दृष्टि से समान होते हैं, उन्हें पर्यायवाची शब्द कहते हैं। इनका अर्थ आपस में मिलताजुलता है, किंतु ये एक दूसरे के स्थान पर प्रयोग किए जा सकते हैं। कुछ शब्द और उनके पर्यायवाची शब्द दिए जा रहे हैं

बहुविकल्पी प्रश्न

1. पर्यायवाची शब्द बताते हैं
(i) एक-सा अर्थ
(ii) विपरीत अर्थ
(iii) भिन्न-भिन्न अर्थ
(iv) इनमें से कोई नहीं

2. कौन-सा शब्द समूह वर्षा का पर्यायवाची है?
(i) वर्ष चतुर्मास
(ii) वृक्ष-वर्ष
(iii) पावस, मेघागम
(iv) वार्षिक, पावस

3. ‘राजा’ का पर्यायवाची शब्द कौन-सा है?
(i) नागपति
(ii) सूपति
(iii) महीपति
(iv) गणपति

4. ‘परिणाम’ का पर्यायवाची है
(i) अप्रयत्न
(ii) प्रयत्नशील
(iii) नतीजा
(iv) चेष्टा

5. ‘निर्णय’ और ‘क्रूर’ का पर्यायवाची है
(i) निर्णय
(ii) निरर्थक
(iii) निश्चय
(iv) बेरहम

6. इनमें कौन-सा शब्द पर्यायवाची नहीं है।
(i) ज्ञान
(ii) शिक्षा
(iii) विद्यार्थी
(iv) सरस्वती

उत्तर-
1. (i)
2. (iii)
3. (iii)
4. (iii)
5. (iv)
6. (iii)

अभ्यास प्रश्न

1. पक्षी, काल, आज्ञा, आग, रोग, वर्षा, क्रोध, प्रकाश, पत्थर, प्रकृति, दया, शोभा, रोग, शत्रुता शब्द के तीन-तीन पर्यायवाची शब्द लिखिए।

2. निम्नलिखित प्रश्नों के लिए सही विकल्प चुनिए
(क) आख
(i) सुमन
(ii) कुसुम
(iii) लोचन
(iv) अंश

(ख) वृक्ष
(i) चीर
(ii) पट
(iii) रैन
(iv) विटप

(ग) तलवार
(i) पानी
(ii) अंबु
(iii) शमशीर
(iv) नीर

(घ) जल
(i) घन
(ii) जलद
(iii) पयोद
(iv) वारि

(ङ) संसार
(i) धाम
(ii) वसुधा
(iii) धरा
(iv) जग

(च) पृथ्वी
(i) अचला
(ii) आलोक
(iii) दीप्ति
(iv) जलद

(ii) विपरीतार्थक या विलोम शब्द

कुछ शब्दों के अर्थ एक दूसरे से उलटे होते हैं। ऐसे शब्द विलोम शब्द कहलाते हैं। इन्हें विपरीतार्थक शब्द भी कहते हैं। इसका अर्थ है- विपरीत (उलटे) अर्थवाले शब्द। जैसे- आगमन X प्रस्थान, उग्र x शांत

बहुविकल्पी प्रश्न

नीचे दिए गए विकल्पों में से सही विलोम पर सही का निशान लगाइए–
1. आदि
(i) अंतिम
(ii) इति
(iii) अंत
(iv) प्रथम

2. स्वस्थ
(i) अस्वस्थ
(ii) रूग्ण
(iii) बीमार
(iv) निरोग

3. परतंत्र
(i) गुलाम
(ii) आज़ाद
(iii) स्वतंत्र
(iv) बंधन

4. प्रकृति
(i) स्वाभाविक
(ii) कृत्रिम
(iii) प्रकृति
(iv) इनमें से कोई नहीं

5. जीवन
(i) आजीवन
(ii) जीवित
(iii) मृत्यु
(iv) मरण

6. शकुन
(i) अशकुन
(ii) अपशकुन
(iii) सगुन
(iv) संयोग

7. आय
(i) आयु
(ii) व्यय
(iii) मितव्ययी
(iv) आमदनी

उत्तर-
1. (iii)
2. (i)
3. (iii)
4. (ii)
5. (ii)
6. (ii)
7.(ii)

अभ्यास प्रश्न

1. नीचे एक शब्द के कई विपरीतार्थक शब्द दिए गए हैं, उनमें से सही शब्द चुनिए
(क) मिथ्या
(i) सच्चा
(ii) सत्य
(iii) सही
(iv) शोक

(ख) कायर
(i) कमजोर
(ii) वीर
(iii) दुर्बल
(iv) बलवान

(ग) लाभ
(i) नुकसान
(ii) व्यय
(iii) हानि
(iv) कभी

(घ) जटिल
(i) सरल
(ii) कठोर
(iii) कोमल
(iv) सख्त

(ङ) राजा
(i) रंक
(ii) प्रजा
(iii) साधु
(iv) फकीर

(च) देश
(i) विदेश
(ii) परदेश
(iii) गाँव
(iv) स्वदेश

(छ) हार
(i) विजय
(ii) युद्ध
(iii) जीत
(iv) सफलता

(ज) निरर्थक
(i) सार्थक
(ii) असार्थक
(iii) अनिरर्थक
(iv) समर्थक

2. निम्नलिखित शब्दों के विलोम शब्द लिखिए-
मुक्ति, भय, प्रातः, स्तुति, सुलभ, परोक्ष, संधि
शोक, पूर्व, मुक्ति, अपमान, सरस, संयोग, सदाचार
मौखिक, गृहस्थ, निरर्थक, शीत, आकाश, उर्वर

3. रेखांकित शब्दों के उचित विलोम से वाक्य पूरा कीजिए।
(i) भारत की मैत्री का जवाब पाकिस्तान ने _____ से दिया।
(ii) पांडवों ने खांडव वन की बंजर भूमि ____ बना डाली।
(iii) वैज्ञानिक आविष्कार हमारे लिए वरदान भी होते हैं और ____ भी।
(iv) इस समस्या की न आदि को पता है और न ____ का।
(v) आयुष का स्वभाव सरल है पर उसके भाई का _____

(iii) अनेकार्थी शब्द
जिन शब्दों के एक से अधिक अर्थ होते हैं, उन्हें अनेकार्थी शब्द कहा जाता है। जैसे–पत्र, कर आदि। ‘पत्र’ का अर्थ पत्ता तथा ‘चिट्ठी’ आदि होता है। इसी प्रकार ‘कर’ का अर्थ हाथ, टैक्स आदि।
ऐसे ही कुछ शब्द व उनके अनेकार्थ यहाँ दिए गए हैं-

अंक – गिनती, नाटक के भाग, गोद, संख्या
ग्रहण – धारण करना, सूर्य या चंद्र ग्रहण
कुल – सब, वंश
रस – आनंद, प्रेम, तत्व सार अंबर-आकाश, वस्त्र, एक सुगंधित पदार्थ
हार – पराजय, फूलों की माला
अनंत – ईश्वर, विष्णु, आकाश
सूत – धागा, सारथी
अपेक्षा – तुलना में, आशा, उम्मीद
नग – पर्वत, नगीना
अर्थ – ऐश्वर्य, धन, प्रयोजन
चर – सेवक, दूत, पक्षी
गति – मोक्ष, दशा, चाल
पद – शब्द, चरण, ओहदा
धन – बादल, घंटा, हथौड़ा
हार – पराजय, माला
चर – सेवक, दूत, पक्षी
लक्ष्य – निशाना, उद्देश्य
जलज – चंद्रमा, मोती, कमल
गुरु – शिक्षक, बड़ा, चालाक
पद – पैर, उपाधि, स्थान
काल – समय, मृत्यु, यमराज
पशु – मूर्ख, चौपाया
पट – वस्त्र, दरवाजा, परदा
पय – दूध, अमृत, पानी
तीर – बाण, किनारा।
मत – राय, संप्रदाय, नकारात्मक भाव

बहुविकल्पी प्रश्न

दिए गए रेखांकित शब्दों के अनेकार्थी शब्द समूह पर सही का चिह्न लगाओ
1. धर
(i) हर, पट
(ii) घड़ा, मन
(iii) तन, मन
(iv) पानी, घड़ा

2. गति
(i) गाना, गिनना
(ii) मोक्ष, चाल
(iii) दशा, दिशा
(iv) गीत, गीता

3. कनक
(i) कंचन, कानन
(ii) कंगन, गेहूँ
(iii) गेहूँ, सोना
(iv) इनमें से कोई नहीं

4. अर्थ
(i) अनर्थ, नाश
(ii) घंटा घटी
(iii) धन, प्रयोजन
(iv) व्यर्थ, धन

5. घन
(i) घर, घंटा
(ii) घंटा, घंटी
(iii) घन, घटा
(iv) बादल, हथौड़ा

उत्तर-
1. (ii)
2. (ii)
3. (iii)
4. (iii)
5. (iv)

अभ्यास प्रश्न

1. नीचे लिखे शब्दों के दो-दो अर्थ लिखिए
कल ____ ____
कुल ____ ____
बाल ____ ____
अक्षर ____ ____
मान ____ ____
नग ____ ____

2. नीचे लिखे शब्द के दो-दो ऐसे वाक्य बनाओ जिससे उनके अनेकार्थ स्पष्ट हों।
अग्र, कनक, पत्र, ग्रहण, हार, अर्थ अंक, गुरु, पत्र, पट

IV. अनेक शब्दों के लिए एक शब्द

जिन शब्दों का प्रयोग वाक्यांश या अनेक शब्दों के स्थान पर किया जाता है, उन्हें अनेक शब्दों के लिए एक शब्द कहते हैं। कम से कम शब्दों में अपने भावों को अभिव्यक्त करना अच्छी भाषा के प्रदर्शन का उदाहरण है। हमें भी कम से कम शब्दों में अपने विचारों को कहने का अभ्यास करना चाहिए। इनके प्रयोग से भाषा में संक्षिप्तता आती है और वह अधिक सुंदर बन जाती है। हिंदी में ऐसे अनेक शब्द हैं। ऐसे ही कुछ अनेक शब्दों के लिए एक शब्द यहाँ दिए गए हैं

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NCERT Exemplar Class 9 Science Chapter 3 Atoms and molecules are part of NCERT Exemplar Class 9 Science. Here we have given NCERT Exemplar Class 9 Science Solutions Chapter 3 Atoms and Molecules.

NCERT Exemplar Class 9 Science Solutions Chapter 3 Atoms and Molecules

Multiple Choice Questions

Question 1.
Which of the following correctly represents 3# 360 g of water?
(i) 2 moles of H20
(ii) 20 moles of water
(iii) 6.022 x 1023 molecules of water
(iv) 1.2044 x102S molecules of water
(a) (i)
(b) (i) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv)
Solution:
(d)
(i) 1 molt of water = 18 g 2 moles of water = 2 x 18 g = 36 g
(ii) 20 moles of water = 18 x 20 = 360 g
(iii) 6.022 x 10²³ molecules of water
= 1 mole = 18 g
(iv) 1 mole of water = 6.022 x 10²³ molecules
6.22 x 10²³ molecules = 1 mole
1.2044 x 10²⁵molecules =

= 20 moles = 20 x 18 = 360 g

Question 2.
Which of the following statements is not true about an atom?
(a) Atoms are not able to exist independently.
(b) Atoms are the basic units from which molecules and ions are formed.
(c) Atoms are always neutral in nature.
(d) Atoms aggregate in large numbers to form the matter that we can see, feel or touch.
Solution:
(a) Atoms of inert gases exist in monoatomic or independent form.

Question 3.
The chemical symbol for nitrogen gas is
(a) Ni
(b) N₂
(c)N⁺
(d) N
Solution:
(b) Nitrogen gas exists as a diatomic molecule hence, its symbol is N2.

Question 4.
The chemical symbol for sodium is
(a) So
(b) Sd
(c) NA
(d) Na
Solution:
(d) Chemical symbol for sodium is Na.

Question 5.
Which of the following would weigh the highest?
(a) 0.2 mole of sucrose (C₁₂H₂₂O₁₁)
(b) 2 moles of CO₂
(c) 2 moles of CaCO3
(d) 10 moles of H₂O
Solution:
(c)Weight = Numberpf moles x molar mass.
0.2 mole of sucrose (C₁₂H₂₂O₁₁) = 0.2 x 342
= 68.4 g
2 moles of CO₂ = 2 x 44 = 88 g
2 moles of CaCO3 = 2 x 100 = 200 g
10 moles of H₂O = 10 x 18 = 180 g

Question 6.
Which of the following has maximum number of atoms?
(a) 18g of H₂O
(b) 18g of O₂
(c) 18g of CO₂
(d) 18 g of CH4
Solution:
(d) Number of atoms =

Question  7.
Which of the following contains maximum number of molecules?
(a) 1g CO₂ (b) 1g N₂
(c) 1g H₂ (d) 1g CH4
Solution:
(c) ag of CO₂=1/44 x 6.022 x 10²³ molecules
= 1.368 x 10²²molecules

Question  8.
Mass of one atom of oxygen is
(a)
(b)
(c)
(d)8 u
Solution:
Mass of one atom of oxygen
=Atomic mass/N

Question  9.
3.42 g of sucrose are dissolved in 18 g of water in a beaker. The number of oxygen atoms in the solution are
(a) 6.68 x10²³
(b) 6.09 x10²²
(c) 6.022 x 10²³
(d) 6.022.x 10²¹
Solution:
(a) Number of moles of sucrose
3.42/342=0.01 mol

Question  10.
A change in the physical state can be brought about
(a) only when energy is given to the system
(b) only when energy is taken out from the system
(c) when energy is either given to, or taken out from the system
(d) without any energy change.
Solution:
(c) When energy is given to the system the solid state changes to liquid. When energy is taken out from a liquid it changes to solid e.g., ice changes to water and water to water vapours when heat energy is given. Water vapours or steam condense to water and water freezes to ice when energy is decreased.

Short Answer Type Questions

Question 11.
Which of the following represents a correct chemical formula? Name it.
(a) CaCl
(b) BiPO4
(c) NaSO4
(d) NaS
Solution:
(a) The correct formula is CaCl2 (valency of Ca = 2, valency of Cl = 1).
(b) is correct because valency of Bi = 3, valency of PO4 = 3
(c) The correct formula is Na₂S0₄ (valency of Na = 1, Valency of S0₄ = 2).
The correct formula is Na₂ (valency of Na = 1, valency of sulphide = 2).
Thus, the correct formula is BiP0₄ and the name is bismuth phosphate.

Question 12.
Write the molecular formulae for the following compounds:
(a) Copper (II) bromide
(b) Aluminium (III) nitrate
(c) Calcium (II) phosphate
(d) Iron (III) sulphide
(e) Mercury (II) chloride
(f) Magnesium (II) acetate.
Solution:
(a) Copper(II) Bromide – cuBr2
(b) Aluminium(III) nitrate – A1(N03)3
(c) Calciuih(II) phosphate – Ca3(PO4)2
(d) Iron(III) sulphide – Fe2S3
(e) Mercury(II) chloride – HgCl2
(f) Magnesium(II) acetate – Mg(CH3COO)2

Question 13.
Write the molecular formulae of all the compounds that can be formed by the combination of following ions:

Solution:

Question 14.
Write the cations and anions present (if any) in the following compounds:
(a) CH3COONa
(b) NaCl
(c) H3
(d) NH4NO3
Solution:

Question 15.
Give the formulae of the compounds formed from the following sets of elements:
(a) Calcium and fluorine
(b) Hydrogen and sulphur
(c) Nitrogen and hydrogen
(d) Carbon and chlorine
(e) Sodium and oxygen
(f) Carbon and oxygen
Solution:
(a) Calcium fluoride – CaF2
(b) Hydrogen sulphide – H2S
(c) Ammonia – NH3
(d) Carbon tetrachloride – CCl4
(e) Sodium oxide – Na20
(f) Carbon monoxide – CO
(g(Carbon dioxide – C02

Question 16.
Which of the following symbols of elements are incorrect? Give their correct symbols.
(a) Cobalt –  CO
(b) Carbon –  c
(c) Aluminium – AL
(d) Helium – He
(e) Sodium –  So
Solution:
(a) Cobalt-Co
(b) Carbon – C
(c) Aluminium-A1
(d) Helium – He (correct)
(e) Sodium-Na

Question 17.
Give the chemical formulae for the following compounds and compute the ratio by mass of the combining elements in each one of them. You may use appendix -111
(a) Ammonia
(b) Carbon monoxide
(c) Hydrogen chloride
(d) Aluminium fluoride
(e) Magnesium sulphide.
Solution:

Question 18.
State the number of atoms present in each of the following chemical species:
(a) CO₃^2-
(b) PQ₄^3-
(c) P₂0₅
(d) CO
Solution:

Question 19.
What is the fraction of the mass of water due to neutrons?

Question 20.
Does the solubility of a substance change with temperature? Explain with the help of an example.
Solution:
Yes, solubility of a substance changes with temperature. It generally increases with temperature. More sugar can be dissolved in hot water as compared to cold water.

Question 21.
Classify each of the following on the basis of their atomicity:

Solution:
Monoatomic with atomicity (1) = He, Ag

Question 22.
You are provided with a fine white coloured powder which is either sugar or salt. How would you identify it without tasting?
Solution:
On heating, sugar powder is charred and becomes black while salt does not char. When dissolved in water, salt solution will conduct electricity because it is ionic while sugar solution will not conduct electricity because it is covalent.

Question 23.
Calculate the number of moles of magnesium present in a magnesium ribbon weighing 12 g. Molar atomic mass of magnesium is 24 g mol-1. Solution:
Atomic mass of Mg = 24 g mol-1
24 g of Mg = 1 mol
12 g of Mg = 12/24 = 0.5 mol

Long Answer Type Questions

Question 24.
Verify by calculating that
(a) 5 moles of CO2 and 5 moles of H2O do not have the same mass.
(b) 240 g of calcium and 240 g magnesium elements have a mole ratio of 3:5.
Solution:
(a) Mass of one mole CO2=44g

Question 25.
Find the ratio by mass of the combining elements in the following compounds. (You may use appendix -111)

Question 26.
Calcium chloride, when dissolved in water, dissociates into its ions according to the following equation:


Question 27.
The difference in the mass of 100 moles each of sodium atoms and sodium ions is 0.0548002 g. Compute the mass of an electron.
Solution:
Number of electrons in Na atom = 11
Number of electrons in Na+ = 10
For 1 mole of Na atom and Na+ the difference in electrons = 1 mole
For 100 moles of Na atoms and Na ions the
difference = 100 moles of electrons
Mass of 100 moles of electrons = 0.0548002 g

Question 28.
Cinnabar (HgS) is a prominent ore of mercury. How many grams of mercury are present in 225 g of pure HgS? Molar mass of Hg and S are 200.6 g mol-1 and 32 g mol-1 respectively.
Solution:
Molar mass of HgS = 200.6 + 32 = 232.6 g
Mass of Hg in 232.6 g of HgS = 200.6 g

Question 29.
The mass of one steel screw is 4.11g. Find the mass of one mole of these steel screws. Compare this value with the mass of the Earth (5.98 x 1024 kg). Which one of the two is heavier and by how many times?
Solution:
Mass of 21 screw = 4.11 g

Question 30.
A sample of vitamin C is known to contain 2.58 x1024 oxygen atoms. How many moles of oxygen atoms are present in the sample?
Solution:
Number of oxygen atoms in the sample=2.58 x 10²⁴

Question 31.
Raunak took 5 moles of carbon atoms in a container and krish also took 5 moles of sodium atoms in another container of same weighty.
(a) Whose container is heavier?
(b) Whose container has more number of atoms?
Solution:
(a) Mass of container containing 5 moles of C atoms=5 x 12 = 60 g
Mass of caontaner containing 5 moles of Na atoms=5 x 23 = 115 g
Hence, container of Krish is heavier.
(b) Both containers have same number of atoms since they co0ntailn same number of moles.

Question 32.
Fill in the missing data in the Table 3.1

Solution:

Question 33.
The visible universe is estimated to contain 1022 stars. How many moles of stars are present in the visible universe?
Solution:


Question 34.
What is the SI prefix for each of the following multiples and submultiples of a unit?

Solution:
(a) 10³ = kilo

Question 35.
Express each of the following in kilograms
(a) 5.84 x 10^-3mg
(b) 58.34 g
(c) 0.584 g
(d) 5.873 x 10- 21g
Solution:
(a) 5.84 x  10^-3mg

Question 36.
Compute the difference in masses of 103 moles each of magnesium atoms and magnesium ions.(Mass of an electron=9.1 x 10^{-31 kg}
Solution:
Mg⁺²ion= 10 electron

Question 37.
Which has more number of atoms? 100fg of N₂ or 100 g of NH3
Solution:
(i) 100 g of N₂ =100/28moles

Question 38.
Compute the number of ions present in 5.85 g of sodium chloride.
Solution:
1 mole of NaCl =23+35.5=58.5 g of NaCl
Number of moles in 5085 g of NaCl
=5085/58.5=0.1 moles
Each NaCl formula unit=Na⁺+ Cl^–
=2 ions

Question 39
A gold sample contains 90% of gold and the rest copper. How many atoms of gold are present in one gram of this sample of gold?
Solution:
1 g of gold sample contains

Question 40.
What are ionic and molecular compounds? Give examples.
Maim Ionic compounds are made up of ions. An ionic compound contains a cation which is a positive ion and an anion which is a negative ion e.g., sodium chloride is an ionic compound made up of Na⁺ and Cl^– ions.
A molecular compound is made up of molecules e.g. ammonia (NH₃), carbon dioxide (CO₂).

Question 41.
Compute the difference in masses of one mole each of aluminium atoms and one mole of its ions. (Mass of an electron is 9.1 x 10-28 g). Which one is heavier?
Solution:

Difference = 27 – 26.9984 = 0.0016 g
1 mole of Al atoms is heavier than 1 mole of Al³⁺ions.

Question 42.
A silver ornament of mass ‘m’ gram is polished with gold equivalent to 1% of the mass of silver. Compute the ratio of the number of atoms of gold and silver in the ornament.
Solution:

Question 43.
A sample of ethane (C₂H₆) gas has the same mass as 1.5 x 102° molecules of methane (CH₄). How many C₂H₆molecules does the sample of gas contain?
Solution:
Molar mass of CH₄=12+4=16 g mol^-1

Question 44.
(a) In a chemical reaction, the sum of the masses of the reactants and products remains unchanged. This is called _____.
(b) A group of atoms carrying a fixed charge on them is called _____.
(c) The formula unit mass of Ca3(P04)2 is _____.
(d) Formula of sodium carbonate is _____. and that of ammonium sulphate is _____.
Solution:
(a) Law of conservation of mass
(b) Polyatomic ion
(c) 310

Question 45.
Complete the following crossword puzzle (Fig. 3.1) by using the name of the chemical elements. Use the data given in Table 3.2 Table 3.2

Solution:

Question 46.
a) In this crossword puzzle (Fig. 3.2), names of 11 elements are hidden. Symbols of these are given below. Complete the puzzle.
1. Cl
2. H
3. Ar
4. 0
5. Xe
6. N
7. He
8. F
9. Kr
10. Rn
11. Ne

(b) Identify the total number of inert gases, their names and symbols from this crossword puzzle.
Solution:

Question 47.
Write the formulae f8r the following and
calculate the molecular mass for each one of them:
(a) Caustic potash
(b) Baking powder
(c) Lime stone
(d) Caustic soda
(e) Ethanol
(f) Common salt
Solution:
(a) caustic potash, KOH

=(39+16+1)=56gmol-

Question 48.
In photosynthesis, 6 molecules of carbon dioxide combine with an equal number of water molecules through a complex series of reactions to give a molecule of glucose having a molecular formula C6H1206. How many grams of water would be required to produce 18 g of glucose? Compute the volume of water so consumed assuming the density of water to be 1 g cm-3.
Solution:

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CBSE Class 8 English Grammar Phrasal Verbs are part of NCERT Solutions for Class 8 English. Here we have given CBSE Class 8 English Grammar Phrasal Verbs.

CBSE Class 8 English Grammar Phrasal Verbs

Prepositions may combine with verbs to form a type of compound verb. This verb + preposition is called phrasal verb. The meaning of a phrasal verb is quite different from the meaning of the verb without that preposition. Look at some examples.

Use of Phrasal Verb

1. Phrasal verb may be transitive or intransitive. In other words, it may or may not have an object.
The plane took off at 4 O’clock.
He took off his hat. or He took his hat off.

2. As you might have noticed in the above example, if the phrasal verb has no object, the particle or the preposition follows it.
He set off for London.
The car broke down on the freeway.

3. If the phrasal verb has an object, the particle i.e., the prepositional part of the phrasal verb, follows the object.
He gave it away.
Break your expenditure down into bills, food and other.
Note : In some cases, the phrasal verb is non-separable :
My parents look after me well.
He called on the doctor.

Exercise 1
(Solved)

Fill in the blanks with suitable preposition :
1. My friend asked me …….. information.
2. Your father asked ……….. you.
3. We have to fight ………… a principle.
4. We must fight ………. poverty.
5. Have you heard ………… Gandhiji ?
6. I haven’t heard ……….. you since long, though you had promised to write.
7. He quarrels ………… everybody.
S. Do not quarrel ………. trifles.
9. She comes ………. well in interviews.
10. How did you come ……… that scratch on your cheek ?
Answers:
1. for
2. about
3. for
4. against
5. of
6. from
7. with
8. over
9. off
10. by

Exercise 2

Match the following groups :

Multiple Choice Questions

Fill in the blanks in the following sentences choosing the correct option from those given in the brackets.
1. He will bear ………. (in/out/with/as) the truth of my statement.
2. The storm has blown ………. (away/out/over/in).
3. The war broke ……… (down/into/up/out) In China.
4. I tried to bring him ……… (about/out/round/up).
5. The strike was called ……… (off/at/on/in) by his speech.
6. The audience were carried ………. (away/off/on/out).
7. How did you come ……… (about/by/across/off) this pen ?
8. He cut his son ……….. (down/short/off/up) without a penny.
9. My advice fell ………… (through/in/off/flat) on him.
10. He got ………. (on/about/over/up) all his difficulties.
11. The President gave ………. (away/back/in/to) the prizes.
12. Do not go ………… (about/back/out/off) on your words.
Answers:
1. out
2. over
3. out
4. round
5. off
6. away
7. by
8. off
9. flat
10. over
11. away
12. back.

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CBSE Class 7 Hindi Grammar वर्ण विचार Pdf free download is part of NCERT Solutions for Class 7 Hindi. Here we have given NCERT Class 7 Hindi Grammar वर्ण विचार.

CBSE Class 7 Hindi Grammar वर्ण विचार

वर्ण – वर्ण वह ध्वनि है जिसके और खंड (टुकड़े) नहीं किए जा सकते; जैसे- अ, इ – क, चु, ख, र इत्यादि।
वर्ण के भेद – वर्ण के दो भेद होते हैं-

1. स्वर
2. व्यंजन

वर्णमाला – वर्गों के व्यवस्थित रूप को वर्णमाला कहते हैं। प्रत्येक भाषा की अपनी वर्णमाला होती है। हिंदी वर्णमाला में ग्यारह स्वर और 33 व्यंजन हैं।

1. स्वर – जिन वर्णो को बोलने के लिए अन्य ध्वनियों का सहारा नहीं लेना पड़ता, उन्हें स्वर कहते हैं। स्वरों के उच्चारण में हवा हमारे मुख से बिना किसी रुकावट के निकलती हैं। हिंदी में ग्यारह स्वर हैं, अ, आ, इ, ई, उ, ऊ, ऋ, ए, ऐ, ओ, औ।

2. व्यंजन – जिन वर्गों का उच्चारण स्वरों की सहायता से होता है, उन्हें व्यंजन कहते हैं। व्यंजन के उच्चारण में ‘अ’ स्वर की सहायता लेनी पड़ती है।
जैसे-

स्वर के भेद
उच्चारण में लगने वाले समय के आधार पर स्वरों के तीन भेद होते हैं।

1. ह्रस्व स्वर
2. दीर्घ स्वर
3. प्लुत स्वर

1. ह्रस्व स्वर – ‘ह्रस्व’ का अर्थ है-लघु अथवा छोटा। जिन स्वरों के उच्चारण में कम समय लगता है, उन्हें हम ह्रस्व स्वर कहते हैं। ये कुल चार हैं-अ, इ, उ, ऋ।।

2. दीर्घ स्वर – दीर्घ का अर्थ है-बड़ा। जिन स्वरों के उच्चारण में ह्रस्व स्वरों की अपेक्षा अधिक समय लगता है, उन्हें दीर्घ स्वर कहते हैं। ये कुल सात हैं-आ, ई, ऊ, ए, ऐ, ओ, औ।।

3. प्लुत स्वर – इसके उच्चारण में सबसे अधिक समय लगता है। इसका प्रयोग केवल संस्कृत में किया जाता है; जैसे ओम–यहाँ ‘इ’ प्लुत का चिह्न है।

व्यंजन के भेद
व्यंजन के तीन भेद हैं-

1. स्पर्श व्यंजन
2. अंतस्थ व्यंजन
3. ऊष्म व्यंजन।

1. स्पर्श व्यंजन – स्पर्श यानी छूना। जिन व्यंजनों के उच्चारण के समय श्वास वायु और जिह्वा मुख के भागों को स्पर्श करती हैं, वे स्पर्श व्यंजन कहलाते हैं। कु से मु तक 25 स्पर्श व्यंजन हैं।
क वर्ग का उच्चारण स्थल कंठ है।
च वर्ग का उच्चारण स्थल तालु है।
ट वर्ग का उच्चारण स्थल मूर्धा है।
त वर्ग का उच्चारण स्थल दाँत है।
प वर्ग का उच्चारण स्थल होठ है।

2. अंतस्थ व्यंजन – मध्य/बीच = स्थित। इन व्यंजनों का उच्चारण स्वर तथा व्यंजन के मध्य का – सा होता है। उच्चारण के समय जिवा मुख के किसी भाग को स्पर्श नहीं करती। ये चार है- य, र, ल, व।

3. ऊष्म व्यंजन – ऊष्म = गर्म। इन व्यंजनों के उच्चारण के समय वायु मुख से रगड़ खाकर ऊष्मा पैदा करती है। यानी उच्चारण के समय मुख से गर्म हवा निकलती है। ये चार हैं- श, ष, स, ह।।

मात्राएँ
स्वरों के लिए निर्धारित चिह्न मात्राएँ कहलाती हैं।
‘अ’ स्वर के अतिरिक्त सभी स्वरों के मात्रा चिह्न होते हैं।

अनुस्वार और विसर्ग – हिंदी वर्णमाला के अनुस्वार (‘) तथा विसर्ग (:) को ‘अ’ के साथ जोड़कर ‘अं’ और अ: लिखा जाता है। और प्रायः इन्हें स्वरों के साथ रखा जाता है क्योंकि इनका उच्चारण स्वरों के साथ ही होता है; जैसे- गंगा, चंदा, प्रातः, अतः आदि। परंतु ये स्वर नहीं हैं। संस्कृत में इन्हें ‘अयोगवाह’ कहा जाता है क्योंकि ये ‘अ’ की सहायता से ही बोले जाते हैं।

अनुनासिक – इनका उच्चारण नाक और गले दोनों से होता है; जैसे- चाँद, गाँधी, आँगन, आदि इसका चिह्न (*) होता है। अनुस्वार वर्णमाला के पंचम वर्ण के स्थान पर प्रयोग में आता है।

विसर्ग (:) – यह ‘ह’ के समान उच्चारित होता है; जैसे- चाँद, साँस, हँस आदि। अनुस्वार और अनुनासिक के उच्चारण में यदि ध्यान न रखा जाए तो हँस (क्रिया शब्द) हँस (पक्षी) बन जाएगा।

हलंत – जब व्यंजन वर्ण स्वर के बिना लिखे जाते हैं तो हलंत ( ) का प्रयोग होता है, जैसे क् च् ट् आदि।

अर्ध चंद्र – यह विदेशी ध्वनि जिसे आगत नाम से जाना जाता है। इसका प्रयोग अंग्रेजी भाषा के शब्दों में किया जाता है; जैसे-डॉक्टर, ऑफ़िसर, कॉलोनी, कॉफ़ी आदि।

वर्ण-संयोग – वर्णो का मेल वर्ण संयोग कहलाता है। क्ष, त्र, ज्ञ संयुक्त वर्ण है, जो क् + ष = क्ष, त् + र = त्र ज + अ = ज्ञ बनते हैं। जब एक व्यंजन अपने जैसे दूसरे व्यंजन से मिलता है तो उसे वित्व व्यंजन कहते हैं; जैसे-पक्का (क् + क)।।

बहुविकल्पी प्रश्न

1. भाषा की सबसे छोटी लिखित इकाई है
(i) पद
(ii) वाक्य
(iii) शब्द
(iv) वर्ण

2. इनमें से कौन-सा स्वर नहीं है
(i) अ
(ii) ओ
(iii) ऊ
(iv) ज

3. इनमें से कौन-सा व्यंजन नहीं है
(i) क
(ii) च
(iii) ट
(iv) ए

4. ‘स्वर’ वर्गों के कितने भेद होते हैं
(i) तीन
(ii) चार
(iii) छह
(iv) सात

5. हिंदी में व्यंजनों की संख्या कितनी है
(i) सैंतीस
(ii) छत्तीस
(iii) अड़तीस
(iv) पैंतीस

6. जिन स्वरों के उच्चारण में अधिक समय लगे, वे कहलाते हैं
(i) स्वर
(ii) व्यंजन
(iii) मात्रा
(iv) प्लुत स्वर

7. जिन व्यंजनों के उच्चारण में जिह्वा मुख के विभिन्न स्थानों को छूती है, वे हैं
(i) संयुक्त व्यंजन
(ii) स्पर्श व्यंजन
(iii) ऊष्म व्यंजन
(iv) इनमें से कोई नहीं

8. एक से अधिक व्यंजन जब जोड़कर बोले या लिखे जाते हैं वे कहलाते हैं
(i) स्वर
(ii) व्यंजन
(iii) संयुक्ताक्षर
(iv) इनमें से कोई नहीं

9. विसर्ग का चिह्न है
(i) (‘)
(ii) (ँ)
(iii) (:)
(iv) (,)

10. स्वरों के उच्चारण में सहायता लेनी पड़ती है
(i) स्वर की
(ii) व्यंजन की
(iii) मात्रा की
(iv) किसी की नहीं

उत्तर-
1. (iv)
2. (iv)
3. (iv)
4. (i)
5. (i)
6. (iv)
7. (iii)
8. (iii)
9. (iii)
10. (ii)

We hope the given CBSE Class 7 Hindi Grammar वर्ण विचार will help you. If you have any query regarding CBSE Class 7 Hindi Grammar वर्ण विचार, drop a comment below and we will get back to you at the earliest.

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UPSEE Application Form 2020: Dr. APJ Abdul Kalam Technical University releases the Application Form for UPSEE in an online mode. The University releases the form for the candidates who are planning on applying for the state exam. The forms will release tentatively in January 2020. The candidates qualifying this exam are eligible to proceed for the admission to the institutes affiliated to AKTU, Uttar Pradesh.

The University organizes Uttar Pradesh State Entrance Exam (UPSEE) for the enrollment in Undergraduate and Postgraduate courses in various fields. Aspirants planning on pursuing their career in Engineering after class 12^th can also appear for this exam. The candidate must fill the Application Form and submit it before the due date. It is an important procedure to follow. The University will also release the Information Brochure along with the Application Form. For more details, read the article below.

UPSEE Application Form Dates 2020

The candidates applying for the UPSEE Exam must know the official dates. The applicant must keep visiting the website on a regular basis for the updates. The Schedule will mention the important dates and events. Candidates must make sure that they do not miss the admission procedure, they cannot proceed otherwise.

Find the tentative UPSEE Application Form 2020 Schedule from the tabular format below

UPSEE Application Form 2020

AKTU will release UPSEE Application Form 2020 in an online mode on the official website. Candidates must fill and submit the form before the due date. Only the candidate submitting the form can proceed with the admission procedure further. There are various sections in the Application that the applicant must fill. They must make sure that the details in the form are valid and correct. The authorities will cross-check the information during the final admission. Candidates must read the Information Brochure very carefully before filling the Application Form. The University will release the brochure along with the Application Form.

The candidate has to provide the Personal details, academic information, Contact details and upload documents and photographs in the Application Form. The Brochure mentions the specifications for documents and photographs. The applicant must note that the final form of submission is only after the Application Fee payment. The Application fee amount will vary as per the category to which the candidate belongs. The payment can be done in an online mode through Credit Card, Debit card and Net Banking. The form will release tentatively in January 2020 and the last date to submit the form is in March 2020.

UPSEE Application Form 2020 – Steps to Fill

The candidate applying for the exam must know the steps for filling the form without any error. Information Brochure will also mention the important steps in details. Find the procedure of filling the UPSEE Application Form from below:

Registration and Filling the Application Form :

• The candidate must register themselves first by visiting the official website to create an account.
• They must provide basic details such as Personal information, Academic details, Contact details, etc.
• After the details, the candidate must set up a security question and password. The candidate is provided with the Application Number and Password. This will work as a candidate’s username and Password for future activities.
• Submit the entries and review the Application Form before clicking ‘Final Submit’ button.

Uploading Image and Signature

In this, the candidate has to upload their recent passport size image and signature in the provided section. The specifications for uploading the documents is mentioned in the Information Brochure. The image must be clear and concise. Any unclear or blurry image will be liable for rejection.

Application Fee Payment

The final step for the successful form submission is the Application Fee payment. The payment must be done through Credit Card or Debit Card or Net banking. A transaction number is generated after the successful payment. The applicant must keep it carefully.

Confirmation Page

After the successful Application Fee payment, the candidate must download the confirmation page stating the acceptance of the Application form. They must also take the printout of the confirmation page.

UPSEE Application Form Correction 2020

AKTU provides an opportunity for the candidate for the Application Form correction. This opportunity is for the applicants who have submitted their form with some error. The examination body opens a window for the correction for few days after the Application procedure is over. The candidate has to login in their account using their Username and Password to edit their Application Form. The applicant must note though that the correction is allowed only in few fields. Find them in the points below:

• Date of Birth
• Applicant’s Name
• Parent’s Domicile
• Gender
• Nationality
• Aadhaar Details

The post UPSEE Application Form 2020 | AKTU/UPTU Notification, Application From, Procedure to Apply appeared first on Learn CBSE.

CBSE Class 7 Hindi Grammar शब्द विचार Pdf free download is part of NCERT Solutions for Class 7 Hindi. Here we have given NCERT Class 7 Hindi Grammar शब्द विचार.

CBSE Class 7 Hindi Grammar शब्द विचार

एक से अधिक वर्षों के सार्थक समूह को शब्द कहते हैं, जैसे- मैं, वह, राम, दिल्ली, लोटा, पंकज, पुस्तक आदि। हिंदी भाषा में शब्दों का वर्गीकरण चार आधारों पर किया जाता है।
(क) अर्थ के आधार पर
(ख) विकार के आधार पर
(ग) उत्पत्ति के आधार पर
(घ) बनावट के आधार पर

(क) अर्थ के आधार पर – अर्थ के आधार पर शब्द के दो भेद होते हैं।

1. सार्थक
2. निरर्थक

1. सार्थक शब्द – जिन शब्दों का कोई अर्थ निकलता है, उसे सार्थक शब्द कहते हैं; जैसे खाना, घर, विद्यालय, पुस्तक, कार आदि।
2. निरर्थक शब्द – जिन शब्दों का अर्थ नहीं निकलता है, उसे निरर्थक शब्द कहते हैं; जैसे- हमल, लमक, टमक, पुलटा आदि।

(ख) विकार के आधार पर – विकार के आधार पर शब्द के दो भेद होते हैं

1. विकारी शब्द
2. अविकारी शब्द

1. विकारी शब्द – जो शब्द लिंग, वचन तथा काल से प्रभावित होकर अपना रूप बदलते हैं, उन्हें विकारी शब्द कहते हैं। संज्ञा, सर्वनाम, विशेषण, क्रिया-ये चार प्रकार के विकारी शब्द होते हैं। क्योंकि लिंग, वचन तथा काल की दृष्टि से इनमें विकार उत्पन्न होता है। यानी इसका रूप बदल जाता है।
2. अविकारी शब्द – जो शब्द लिंग वचन तथा काल से प्रभावित नहीं होते तथा हर स्थिति में ज्यों के त्यों बने रहते हैं। उन्हें अविकारी शब्द अव्यय कहते हैं। क्रियाविशेषण, संबंधबोधक, समुच्चयबोधक तथा विस्मयादिबोधक शब्द अविकारी होते हैं; जैसे-ऊपर, नीचे, हाथ! आह! और पर, क्योंकि तो सुबह, इसलिए धीरे वहाँ आदि।

(ग) उत्पत्ति के आधार पर – उत्पत्ति के आधार पर शब्द के चार भेद होते हैं

1. तत्सम
2. तद्भव
3. देशज
4. विदेशी

1. तत्सम शब्द – ये शब्द संस्कृत भाषा से हिंदी भाषा में ज्यों-के-त्यों अर्थात् उसी रूप में ले लिए जाते हैं, जिस रूप में ये संस्कृत में होते हैं; जैसे- सर्प, ग्राम, सत्य, सूर्य, कार्य, प्रथम आदि।
2. तद्भव शब्द – ये शब्द संस्कृत शब्दों के रूप में कुछ बदलाव के साथ हिंदी भाषा में प्रयोग होते हैं; जैसे- दही (दधि), साँप (सर्प), गाँव (ग्राम), सच (सत्य), काम (कार्य) आदि।
3. देशज शब्द – ‘देशज’ अर्थात् देश में उत्पन्न। ये शब्द भारत के विभिन्न क्षेत्रों से तथा आम बोलचाल की भाषा से लिए गए हैं; जैसे-खिचड़ी, जूता, पैसा, पगड़ी आदि।
4. विदेशी शब्द – दूसरे देशों की भाषाओं से हिंदी में आए शब्द ‘विदेशी’ शब्द कहलाते हैं; जैसे- लालटेन, स्टेशन, स्कूल, पादरी, जमीन, बंदूक, सब्ज़ी, आदमी, वकील, सौगात, रूमाल, तौलिया, कमरा आदि।

(घ) बनावट के आधार पर- बनावट के आधार पर शब्द के तीन भेद होते हैं।

1. रूढ़
2. यौगिक
3. योगरूढ़

1. रूढ़ शब्द – वे शब्द जो परंपरा से किसी व्यक्ति, स्थान, वस्तु या प्राणी आदि के लिए प्रयोग होते चले आ रहे हैं। उन्हें रूढ शब्द कहते हैं। इन शब्दों के खंड करने पर इनका कोई अर्थ नहीं निकलता यानी खंड करने पर ये शब्द अर्थहीन हो जाते हैं।
2. यौगिक शब्द – ‘यौगिक’ यानी योग से बनने वाला। वे शब्द जो दो या दो से अधिक शब्दों के योग से बनते हैं, उन्हें यौगिक शब्द कहते हैं। इन शब्दों के खंड किए जा सकते हैं। खंडित शब्दों के भी अर्थ होते हैं। इन शब्दों की रचना उपसर्ग, प्रत्यय, संधि तथा समाज के द्वारा होती है; जैसे- भोजनालय ( भोजन का घर)

बहुविकल्पी प्रश्न

1. शब्द कहलाता है
(i) शब्दों का समूह
(ii) वर्गों का समूह
(iii) वर्गों को सार्थक समूह
(iv) इनमें से कोई नहीं

2. प्रयोग के आधार पर शब्द के भेद होते हैं
(i) विकारी, अविकारी
(ii) शब्द अर्थ
(iii) विलोम, पर्यायवाची
(iv) विलोम एकार्थी

3. रचना के आधार पर शब्दों के भेद हैं
(i) एक
(ii) दो
(iii) तीन
(iv) चार

4. जो शब्द संस्कृत से ज्यों के त्यों हिंदी में आए
(i) तत्सम शब्द
(ii) तद्भव शब्द
(iii) देशज शब्द
(iv) विदेशी शब्द

5. उत्पत्ति के आधार पर शब्द के कितने भेद हैं ?
(i) तीन
(ii) पाँच
(iii) छह
(iv) चार

6. ‘तत्सम शब्द’ किस आधार पर शब्द का भेद है?
(i) रचना
(ii) अर्थ
(iii) प्रयोग
(iv) उत्पत्ति

7. निम्नलिखित में से किस विकल्प में विकारी शब्द है ?
(i) क्रिया
(ii) क्रियाविशेषण
(ii) विस्मयादिबोधक
(iv) समुच्चयबोधक

8. निम्नलिखित में से तत्सम शब्द किस विकल्प में है?
(i) क्षमा
(ii) बंदर
(iii) आग
(iv) फूल

उत्तर
1. (ii)
2. (i)
3. (iii)
4. (i)
5. (iv)
6. (iv)
7. (i)
8. (i)

We hope the given CBSE Class 7 Hindi Grammar शब्द विचार will help you. If you have any query regarding CBSE Class 7 Hindi Grammar शब्द विचार, drop a comment below and we will get back to you at the earliest.

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CBSE Class 7 Science Notes Chapter 15 Light Pdf free download is part of Class 7 Science Notes for Quick Revision. Here we have given NCERT Class 7 Science Notes Chapter 15 Light.

CBSE Class 7 Science Notes Chapter 15 Light

In this world, we usually see a variety of objects. Sometimes, we are unable to see anything in a dark room but on lighting up the room, we are able to see the things in the room. Since, it is an obvious question arising that what makes thing visible.

So, its answer is light. Light is a form of energy which enables us to see objects from where it comes or reflected. We can detect light with our eyes.

Light Travelling along a Straight Line
By seeing the phenomena around us like a beam of sunlight enters a room through a narrow opening or a hole and beams of light coming out from the headlamps of cars, scooters, engines, torch, etc.
From the above examples, we can conclude that light travels along a straight line.

Reflection of Light
There are some certain situations in which a mirror or shiny surfaces like stainless steel plate, shining steel spoon act as a mirror, can change the direction of light that falls on it. So, this process of change in direction of light by a mirror is called a reflection of light. The surface of the water can also act as a mirror and can also change the path of light and that is why we see the reflection of trees or buildings in the water.

Image of An Object
Generally, when we look into a mirror, then we see our face. Actually, what we see in the mirror it is exactly a reflection of our face, hence it is known as an image of our face. In this case, our face is the object and what we see in the mirror is its image. The image of our face seen in the mirror is formed where light rays, after reflection from the mirror, seems to originate from. The image of our face appears to be situated behind the mirror.
There are two types of images:
Real image: It is an image which can be obtained on a screen, e.g. the image formed on a cinema screen. When the light rays coming from an object actually meet at a point after reflection from the mirror, then it results in the formation of a real image.

Virtual image: It is an image which cannot be obtained on a screen, e.g. image formed by a plane mirror. When the light rays coming from an object appear to meet after reflection from the mirror, then it results in the formation of virtual image. It is not possible to form a virtual image on the screen because light rays actually do not pass the screen or cannot be received on a screen.

Characteristics of the Images Formed by a Plane Mirror
Now, we will describe the various characteristics of the images formed in a plane mirror by taking the example of the image of the candle.
(i) When we see the mirror, the image of candle appears to be formed behind the mirror.

(ii) Now, put a vertical screen behind the plane mirror (where the image of candle appears to be situated), then we will notice that the image of candle cannot be formed on the screen. Even if the screen is placed in front of the plane mirror, then the image of candle cannot be formed on the screen. Since, the image of candle formed in the plane mirror cannot be formed on a screen, which means that the image of candle in the plane mirror is a virtual image.

(iii) If we see the figure, then we will find that the length and breadth of the image of the candle and its flame to be the same as that of the original candle and its flame. The image of candle in the plane mirror is of the same size as the original candle.

(iv) Also if we see the figure, then we will find that the candle has a flame at the top and the image of candle also has a flame at the top. So, the top of the candle remains at the top in the image. In the same way, the bottom of candle remains at the bottom in an image. Such an image is called an erect image (or upright image). Therefore, the image formed by a plane mirror is erect.

Side Inversion (Right ⇔ Left)
When we see our image in a plane mirror, is it exactly like us? There is an interesting difference between us and our image. Let us find out this difference with the help of an example.

If we stand in front of a plane mirror and lift our right hand, then we see our image lift its left hand. And if we lift our left hand, then the image appears to lift its right hand.

This means that the right side of our body becomes the left side in the image while the left side of our body becomes the right side of the image. It appears as if our image has been ‘reversed side ways’ with respect to your body. The effect of reversing the sides of an object and its image is called lateral inversion.

So, we say that image formed in a plane mirror is laterally inverted.
So, we can understand why the word AMBULANCE is written as 3DMAJU9MA. When a driver of a vehicle ahead of an ambulance look in his/her rear view mirror, then he/she can read AMBULANCE written on it and give way to it. So, it is the duty of everyone of us to allow an ambulance to pass without blocking its way.

Spherical Mirrors
All the mirrors are not straight like plane mirror as some of the mirrors are curved mirror. There is a common example of a curved mirror, i.e. spherical mirror. A mirror whose reflecting surface is the part of a hollow sphere of glass is known as a spherical mirror.

Image Formed by Spherical Mirror
It is a fact that spherical mirrors form images of the objects placed in front of them. So, these images are formed, when light rays coming from the object fall on the mirror, get reflected and converge or diverge. We can use a spoon in order to understand the image formation by a spherical mirror.

The inside surface of a hollow sphere of glass is bent in or concave but the outside surface is bulging out or convex. So, the spherical mirrors are of two types:

• Concave mirror
• Convex mirror

e.g. A shining steel spoon represents both a convex mirror as well as a concave mirror. As the front side (or inner side) of a spoon is bent inward, so the front side of a shining spoon represents a concave mirror while the back side (or outer side) of a spoon is bulging outward, so the back side of a shining spoon represents a convex mirror as shown in figure.

Concave Mirror (Converging Mirror)
The mirror whose reflecting surface is concave (and polished surface is convex) is called a concave mirror.
The concave mirror reflects the parallel rays of light in such a way that after reflection, all the rays converge (or meet) at one point called focus in front of the mirror. Since a concave mirror converges a beam of parallel light rays. Therefore, a concave mirror is also known as a converging mirror.

Image Formed by a Concave Mirror When the Object is Far Off
A concave mirror forms a real image of the sun. We can understand the formation of the image by a concave mirror when the object is far off by an activity.

Therefore, we can conclude that the image formed by a concave mirror is much smaller than the object (highly diminished) and real because it can be obtained on a sheet of paper (which is a kind of screen).
So, when an object is placed at a far off distance front a concave mirror, then image formed by a concave mirror is

• real
• inverted
• much smaller than the object.

Image Formed by a Concave Mirror When the Object is Placed Close to Concave Mirror
Let us perform an activity to understand the formation of image by a concave mirror when the object is placed close to the concave mirror.

Since the image can be observed only by looking into the concave mirror and cannot be formed on the screen, therefore, the image is virtual. If we look at the image in the concave mirror, we find it to be the same side up as the candle, so the image is erect. And if we compare the size of the candle and its image, then we will find that the image is larger than the candle. Therefore, the image is larger than the object (enlarged or magnified).

Hence, we can conclude that when an object is placed close to a concave mirror, the image formed by the concave mirror is

• virtual
• erect
• larger than the object (enlarged or magnified).

Uses of Concave Mirrors

• To see the large image of teeth of a patient, concave mirrors are used by the dentist.
• In torches, headlights of vehicles and searchlights to get a strong, straight beam of light, etc., concave mirrors are used as reflectors.
• To see a large image of the face, then concave mirrors are used as shaving mirrors.

Convex Mirror (Diverging Mirror)
The mirror whose reflecting surface is bulging or convex (polished surface is concave) is called the convex mirror. After reflection from the convex mirror, the parallel rays of light are spreading out. When the parallel rays of light spread out, we can say that the rays of light are diverging.

Now, we can say that a beam of parallel light rays diverges (spreads out) after reflection from a convex mirror.
Since a convex mirror diverges a beam of parallel light rays, therefore, it is also known as a diverging mirror.

Image Formed By a Convex Mirror
Let us perform an activity to understand the formation of an image by a convex mirror.
The image of the candle can be seen only by looking into the convex mirror and cannot be formed on a screen. It is a virtual image. If we look at the image in the convex mirror, we will find that it is the same side up as the candle. So, the image is erect. And if we compare the size of the candle and its image, the image appears to be smaller. Therefore, the image is smaller in size than the object (or diminished). Even if we change the distance of candle (object) from the convex mirror, we will notice that in every case, the image of the candle formed by the convex mirror remains virtual, erect and smaller in size than the candle.
So, we can conclude that whatever be the distance of the object from a convex mirror, the image formed by a convex mirror is always

• virtual
• erect and
• smaller than the object (or diminished).

Uses of Convex Mirrors

• To see the traffic at the rear side or backside on the road, convex mirrors are used as rear view mirrors or side view mirrors in vehicles such as cars, scooters, buses, etc.
• Big convex mirrors are used as shop security mirrors. By installing a convex mirror in the shop, the shop owner can keep an eye on the customers.

Image Formed by Lenses
Since a lens is a piece of transparent glass bound by the two spherical surfaces. Lenses are transparent so that light can pass through lenses. Lenses are of two types:

• Convex lens
• Concave lens

Get some lens and try to touch them, we will find that some are thicker in the middle than at the edges and some are thinner in the middle than at the edge.

Convex Lens (Converging Lens)
The convex lens is the lens which is thicker in the middle than at the edges. A beam of parallel rays of light falls on a convex lens from the left side. After passing through the convex lens, the beam of parallel rays of light converges at a point as shown in the figure given below. Hence, a convex lens is a converging lens.

Image Formed by a Convex Lens
The nature and size of the image formed by a convex lens depend on the distance of the object from the convex lens.

Thus, we can conclude that when an object is placed at a far off distance from a convex lens, then the image formed by the convex lens is real, inverted and much smaller than the object (or highly diminished).

Now, change the distance of the candle from the lens and try to obtain the image of the candle flame every time on the screen by moving it. So, is it possible to get in any position of the object for which image was erect and, magnified? Yes, it is possible when the candle is placed very close to the convex lens.

Uses of Convex Lenses

• Convex lenses are used as a magnifying glass.
• In the manufacturing of spectacles, camera, microscope, telescope and binoculars, convex lenses are used.

Concave Lens (Diverging Lens)
A concave lens is a lens which is thinner in the middle than at the edge. A parallel beam of light falls on a concave lens as shown in the figure. After passing through the concave lens, the rays of light are diverging (or spreading out).

Since a concave lens diverges light rays falling on it, therefore, it is also called a diverging lens.

Image Formed by a Concave Lens
In the case of a convex lens, we have studied that the nature of image formed depends on the distance of the object from the convex lens. But, this is not followed in the case of a concave lens.
Let us perform an activity to understand the formation of an image by a concave lens.

Uses of Concave Lenses

• In order to see the image of the person standing outside, concave lenses are used in the peepholes in the door of hotel rooms.
• Concave lenses are used in making spectacles.

Sunlight: White or Coloured
We might have noticed a rainbow which usually appears after the rain when the sun is low in the sky. An arc of seven colours seen in the sky is known as the rainbow. The seven colours of a rainbow are red, orange, yellow, green, blue, indigo and violet. We might also have seen that when we blow soap bubbles, they appear colourful. Similarly, when light is reflecting from the surface of a Compact Disc (CD), we can see many colours. The rainbow is produced by the dispersion of sunlight by tiny raindrops suspended in the atmosphere.

Dispersion of Light
In the year 1665, Newton discovered by his experiments with glass prisms that white light (like sunlight) consists of a mixture of lights of seven colours. Newton found that if a beam of white light is passed through a glass prism, then the white light splits to form a band of seven colours on a white screen. The band of seven colours formed on a white screen, when a beam of white light is passed through a glass prism, is known as a spectrum of white light. The seven colours of the spectrum are Red, Orange, Yellow, Green, Blue, Indigo and Violet.

So, dispersion of light is the phenomenon of splitting up of white light into seven colours on passing through a transparent medium like a glass prism. The formation of a spectrum of seven colours indicates that white light is a mixture of seven colours. White light can be sunlight. So, now we can say that sunlight consists of seven colours.
We can mix these colours to get white light. This can be done by using Newton’s disc, let us try this.

We hope the given CBSE Class 7 Science Notes Chapter 15 Light Pdf free download will help you. If you have any query regarding NCERT Class 7 Science Notes Chapter 15 Light, drop a comment below and we will get back to you at the earliest.

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NCERT Exemplar Class 9 Science Chapter 6 Tissues are part of NCERT Exemplar Class 9 Science. Here we have given NCERT Exemplar Class 9 Science Solutions Chapter 6 Tissues.

NCERT Exemplar Class 9 Science Solutions Class 9 Science Chapter 6 Tissues

Multiple Choice Questions

Question 1.
Which of the following tissues has dead cells?
(a) Parenchyma
(b) Sclerenchyma
(c) Collenchyma
(d) Epithelial tissue
Solution:
(b) Sclerenchyma is a simple permanent tissue comprising of dead cells. The cells are long and narrow with lignified cell walls. The cells of sclerenchyma are closely packed without any intercellular spaces. Sclerenchyma tissue is present in stems (around the vascular bundles), roots, veins of leaves, hard covering of seeds and nuts etc. Besides, cells of surface layers in stratified epithelium are dead, but this tissue does not has both dead and living cells unlike sclerenchyma.

Question 2.
Find out incorrect sentence.
(a) Parenchymatous tissues have intercellular spaces.
(b) Collenchymatous tissues are irregularly thickened at corners.
(c) Apical and intercalary meristems are permanent tissues.
(d) Meristematic tissue, in its early stage, lacks vacuoles.
Solution:
(c) Apical and intercalary meristems are not permanent tissues but they are meristematic tissues which remain in continuous state of division. These tissues differentiate to give rise to the permanent tissues.

Question 3.
Girth of stem increases due to
(a) apical meristem
(b) lateral meristem
(c) intercalary meristem
(d) vertical meristem.
Solution:
(b) Lateral meristem occurs on the sides almost parallel to the long axis of the root, stem and its branches. It is responsible for an increase in girth of the stem, i.e. secondary growth.

Question 4.
Which cell does not have perforated cell wall?
(a) Tracheids
(b) Companion cells
(c) Sieve tubes
(d) Vessels
Solution:
(b) Companion cells are narrow, elongated, thin-walled, living cells. They lie on the sides of the sieve tubes and are closely associated with them through plasmodesmata. Companion cells do not possess perforated cell walls.

Question 5.
Intestine absorbs the digested food materials. What type of epithelial cells are responsible for that?
(a) Stratified squamous epithelium
(b) Columnar epithelium
(c) Spindle fibres
(d) Cuboidal epithelium
Solution:
(b) Columnar epithelium consists of pillar-like cells that are much taller than wide. The nuclei are generally elongated along the long axis of cells. It lines the stomach, intestine and gall bladder. Columnar epithelium of intestine is specialised for the absorption of water and digested food.

Question 6.
A person met with an accident in which two long bones of hand were dislocated. Which among the following may be the possible reason?
(a) Tendon break
(b) Break of skeletal muscle
(c) Ligament break
(d) Areolar tissue break
Solution:
(c) It may be ligament break because ligaments serve to bind the bones together. A ligament is an elastic connective tissue which has great strength.

Question 7.
While doing work and running, you move your organs like hands, legs etc. Which among the following is correct?
(a) Smooth muscles contract and pull the ligament to move the bones.
(b) Smooth muscles contract and pull the tendons to move the bones.
(c) Skeletal muscles contract and pull the ligament to move the bones.
(f) Skeletal muscles contract and pull the tendon to move the bones.
Solution:
(d) Skeletal muscles or striated muscles are found in the body wall and the limbs (biceps and triceps of arms, legs). The contraction and relaxation of these muscles are under the control of organism, so they are also called voluntary muscles. These are attached to the bones by tendons. When they contract, they pull the tendon to move the bones and help in the movement of limbs.

Question 8.
Which muscles act involuntarily?
(i) Striated muscles
(ii) Smooth muscles
(iii) Cardiac muscles
(iv) Skeletal muslces
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
Solution:
(b) The muscles which are not under the control of our will, are called involuntary muscles. Smooth (unstriated) muscles and cardiac muscles are involuntary muscles.

Question 9.
Meristematic tissues in plants are
(a) localised and permanent
(b) not limited to certain regions
(c) localised and dividing cells
(d) growing in volume. .
Solution:
(c) Meristematic tissues are groups of living cells which are localised at specific parts in the plant body and divide continuously to add new cells.

Question 10.
Which is not a function of epidermis?
(a) Protection from adverse condition
(b) Gaseous exchange
(c) Conduction of water
(d) Transpiration
Solution:
(c) Epidermis is the outermost layer of cells covering a plant. Its function are principally to protect the plant from injury or adverse conditions and to reduce water loss. It also helps in gaseous exchange and transpiration as it possesses stomata. Conduction of water occurs by xylem which is a complex permanent tissue.

Question 11.
Select the incorrect sentence.
(a) Blood has matrix containing proteins, salts and hormones.
(b) Two bones are connected with ligament.
(c) Tendons are non-fibrous tissue and fragile.
(d) Cartilage is a form of connective tissue.
Solution:
(c) Tendons are white fibrous connective tissues having great strength and join skeletal muscles with bones.

Question 12.
Cartilage is not found in
(a) nose
(b) ear
(c) kidney
(d) larynx.
Solution:
(C) Cartilage is a soft skeletal tissue (a type of connective tissue) which has widely spaced cells. The solid matrix is composed of proteins and sugar. Cartilage smoothens bone surfaces at joints and is also present in the nose, ear, trachea and larynx.

Question 13.
Fats are stored in human body as
(a) cuboidal epithelium
(b) adipose tissue
(c) bones
(d) cartilage.
Solution:
(b) Adipose (connective tissue) is primarily a fat storing tissue in which the matrix is packed with large, spherical or oval fat cells (or adipocytes). Each fat cell contains a large fat globule. The adipose tissue is found beneath the skin, in the covering of the heart, around the blood vessels and kidneys and in yellow bone marrow. This tissue stores fat and insulates the body against heat loss.

Question 14.
Bone matrix is rich in
(a) fluoride and calcium
(b) calcium and phosphorus
(c) calcium and potassium
(d) phosphorus and potassium.
Solution:
(b) Bone is a very strong and non- flexible vertebrate connective tissue which forms the framework that supports the body. The bone matrix contains both inorganic and organic substances. The inorganic salts present in the matrix are mainly phosphates and carbonates of calcium and magnesium e.g. calcium phosphate, calcium carbonate, magnesium phosphate etc.

Question 15.
Contractile proteins are found in
(a) bones
(b) blood
(c) muscles
(d) cartilage.
Solution:
(c) Muscular tissue consists of muscle fibres and is responsible for movement in the body. Muscles contain special proteins called contractile proteins, which contract and relax to cause movement.

Question 16.
Voluntary muscles are found in
(a) alimentary canal
(b) limbs
(c) iris of the eye
(d) bronchi of lungs.
Solution:
(b) Refer to answer 7.

Question 17.
Nervous tissue is not found in
(a) brain
(b) spinal cord
(c) tendons
(d) nerves.
Solution:
(c) The nervous tissue, which contains densely packed nerve cells, called neurons (Gk. neuro = nerve), is present in the brain, spinal cord and nerves. The neurons are specialised for conduction of nerve impulses. Tendon is a type of connective tissue.

Question 18.
Nerve cell does not contain
(a) axon
(b) nerve endings
(c) tendons
(d) dendrites.
Solution:
(c) A nerve cell or neuron comprises of three parts
(i) Cyton or cell body which contains nucleus and cytoplasm with characteristic deeply stained particles called Nissl’s granules.
(ii) Dendrons which are short processes arising from the cyton and further branching into dendrites.
(iii) Axon which is a single, long cylindrical process and forms fine branches terminally (axon endings).

Question 19.
Which of the following helps in repair of tissue and fills up the space inside the organ?
(a) Tendon
(b) Adipose tissue
(c) Areolar
(d) Cartilage
Solution:
(c) Areolar connective tissue is the most widely distributed connective tissue is animal’s body. It is found between the skin and muscles, around blood vessels and nerves, and in the bone marrow. It fills the space inside the organs, supports internal organs and helps in repair of tissues.

Question 20.
The muscular tissue which function through-out the life continuously without fatigue is
(a) skeletal muscle
(b) cardiac muscle
(c) smooth muscle
(d) voluntary muscle.
Solution:
(b) Cardiac muscles are found in the wall of the heart and in the wall of large veins (e.g. pulmonary veins and superior vena cava) where these veins enter the heart. Cardiac muscle fibres are richly supplied with blood vessels and they never get fatigued.

Question 21.
Which of the following cells is found in the cartilaginous tissue of the body?
(a) Mast cells
(b) Basophils
(c) Osteocytes
(d) Chondrocytes
Solution:
(d) Chondrocytes are the cells present in the cartilaginous tissue. These cells produce and maintain the cartilaginous matrix.

Question 22.
The dead element present in the phloem is
(a) companion cells
(b) phloem fibres
(c) phloem parenchyma
(d) sieve tubes.
Solution:
(b) Phloem is a complex permanent tissue of vascular plants which conducts organic food material from leaves to different plant parts. Phloem consists of four types of component viz. sieve tubes, companion cells, phloem parenchyma and phloem fibres. Out of all these components only the phloem fibres are dead and the remaining ones are living.

Question 23.
Which of the following does not lose their nucleus at maturity?
(a) Companion cells
(b) Red blood cells
(c) Vessel
(d) Sieve tube cells
Solution:
(a) Companion cells are narrow, elongated, thin walled, living cells. They have dense cytoplasm and a prominent nucleus. Red blood cells of mammals, vessels (xylem elements) and sieve tube cells (phloem elements) lose their nuclei at maturity.

Question 24.
ln desert plants, rate of water loss gets reduced due to the presence of
(a) cuticle
(b) stomata
(c) lignin
(d) suberin.
Solution:
(a) Cuticle is the continuous waxy layer that covers the aerial parts of a plant. Composed mainly of cutin, it is secreted by the epidermis and its primary function is to prevent water loss.

Question 25.
A long tree has several branches. The tissue that helps in the sideways conduction of water in the branches is
(a) collenchyma
(b) xylem parenchyma
(c) parenchyma
(d) xylem vessels.
Solution:
(b) Xylem (a complex permanent tissue) is the chief conducting tissue of vascular plants responsible for conduction of water and inorganic solutes. The tissue is composed of four kinds of cell: tracheids, vessels (or tracheae), xylem parenchyma and xylem fibres. Vessels and tracheids help in long distance vertical conduction of water and minerals from the roots to different parts of the shoot system. The main stem along with all of its branches are all supplied with water and mineral by mean by xylem vessels and tracheids. Radial conduction i.e., sideways conduction of water occurs by xylem parenchyma.

Question 26.
If the tip of sugarcane plant is removed from the field, even then it keeps on growing in length. It is due to the presence of
(a) cambium
(b) apical meristem
(c) lateral meristem
(d) intercalary meristem.
Solution:
(d) Intercalary meristem is present at the base of intemodes or at the base of nodes and at the base of leaves. This meristem brings about elongation (growth in length) of the part of the plant in which it is present. So even if the tip of the sugarcane plant is removed i.e. apical meristem is removed, it keeps on growing in length due to the activity of intercalary meristem.

Question 27.
A nail is inserted in the trunk of a tree at a height of 1 metre from the ground level. After 3 years the nail will
(a) move downwards
(b) move upwards
(c) remain at the same position
(d) move sideways.
Solution:
(c) The nail will remain at the same position after 3 years, but will appear to have sunk into the tree. This is because of the secondary growth of the tree which increases the girth of a tree. The increase in height of the plant will occur due to primary growth which occurs only in the regions of the apical meristems i.e. at the tips of the main stem or branches. As increase in height of the tree takes place from top only, therefore the nail will remain at the same position as it is inserted near the ground level.

Question 28.
Parenchyma cells are
(a) relatively unspecified and thin walled
(b) thick walled and specialised
(c) lignified
(c) none of these.
Solution:
(a) Parenchyma is a living, simple permanent tissue which consists of relatively unspecified cells with thin walls. The cells contain intercellular spaces. Parenchyma tissue stores food, nutrients, water and performs many other functions.

Question 29.
Flexibility in plants is due to
(a) collenchyma
(b) sclerenchyma
(c) parenchyma
(d) chlorenchyma.
Solution:
(a) Collenchyma is a living, simple permanent tissue which is present below the epidermis in petiole, leaves and stems of herbaceous dicots e.g. sunflower, tomato etc. Collenchyma provides flexibility to the plant parts and allows their easy bending without breaking. Cells of this tissue are elongated, irregularly thickened at the comers with very little intercellular spaces.

Question 30.
Cork cells are made impervious to water and gases by the presence of
(a) cellulose
(b) lipids
(c) suberin
(d) lignin.
Solution:
(c) Cork is the outermost layer of an old woody stem which comprises of dead cells with no intercellular spaces. The cell walls of cork cells are deposited with suberin which makes them impervious to water and gases.

Question 31.
Survival of plants in terrestrial environment has been made possible by the presence of
(a) intercalary meristem
(b) conducting tissue
(c) apical meristem
(d) parenchymatous tissue.
Solution:
(b) Xylem and phloem are the complex permanent tissues which constitute a vascular bundle. Vascular or conducting tissue is a distinctive feature of higher plants, which has made their survival possible in terrestrial environment as .they make it possible for plants to survive without being surrounded with water.

Question 32.
Choose the wrong statement.
(a) The nature of matrix differs according to the function of the tissue.
(b) Fats are stored below the skin and in between the internal organs.
(c) Epithelial tissues have intercellular spaces between them.
(d) Cells of striated muscles are multinudeate and unbranched.
Solution:
(c) Epithelial tissues form the covering or protective tissues in the animal body. The cells of this tissue are tightly packed and form a continuous sheet. They have only a small amount of cementing material between then and almost no intercellular space.

Question 33.
The water conducting tissue generally present in gymnosperm is
(a) vessels
(b) sieve tube
(c) tracheids
(d) xylem fibres.
Solution:
(c) Xylem tissue of gymnosperms lacks the vessels and comprises of tracheids, fibres and parenchyma. Thus, the main water conducting tissue of gymnosperms is xylem tracheid. Sieve tubes translocate food material.

Short Answer Type Questions

Question 34.
Animals of colder regions and fishes of cold water have thicker layer of subcutaneous fat. Describe why?
Solution:
A thick layer of subcutaneous fat functions as an insulating coat that prevents heat loss from the body and helps to keep the body of the animal warm in colder environment. Moreover, fat also functions as reserve food during the periods of scarcity.- Thus, animals of colder regions and fish of cold water have thicker layer of subcutaneous fat.

Question 35.
Match the column (A) with the column (B).Match the column (A) with the column (B).
imageee
Solution:
(a) (v)
(b) (iv)
(c) (iii)
(d) (i)
(e) (ii)

Question 36.
Match the column (A) with the column (B).Match the column (A) with the column (B).
imageee
(a) (i)
(b) (ii)
(c) (iv)
(d) (iii)
(e) (v)

Question 37.
If a potted plant is covered with a glass jar, water vapours appear on the wall of glass jar. Explain why?
Solution:
In a potted plant, transpiration occurs through the stomata present on the surface of leaves. When a potted plant is covered with a glass jar, water vapours released by transpiration condense and appear as water droplets on inner walls of glass jar.

Question 38.
Name the different components of xylem and draw a living component.
Solution:
Different components of xylem are tracheids, vessels, xylem parenchyma and xylem fibres. Xylem parenchyma is the only living component of xylem whose diagram is drawn below:

Question 39.
Draw and identify different elements of phloem.
Solution:
Different elements of phloem are sieve tubes, companion cells, phloem fibres and phloem parenchyma. Different phloem elements are shown in the following diagram:

Question 40.
Write true (T) or false (F).
(a) Epithelial tissue is protective tissue in animal body.
(b) The lining of blood vessels, lung alveoli and kidney tubules are all made up of epithelial tissue.
(c) Epithelial cells have a lot of intercellular spaces.
(d) Epithelial layer is permeable layer.
(e) Epithelial layer does not allow regulation of materials between body and external environment.
Solution:
(a) T
(b) T
(c) F – Epithelial cells have almost no intercellular spaces.
(d) T
(e) F – Due to its permeability, epithelial layer plays an important role in regulating exchange of materials between body and external environment.

Question 41.
Differentiate between voluntary and involuntary muscles. Give one example of each type.
Solution:
Voluntary muscles are the muscles which are under the control of our will e.g. skeletal muscles. Muscles present in our limbs (arms and legs) are skeletal muscles and can be moved by our conscious efforts. not under the control of our will, e.g., smooth muscles and cardiac muscles. Muscles present in stomach, intestine etc. are smooth muscles and muscles present is our heart are cardiac muscles, which cannot be moved by our conscious efforts.

Question 42.
Differentiate the following activities on the basis of voluntary (V) or involuntary (I V) muscles.
(a) Jumping of frog
(b) Pumping of the heart
(c) Writing with hand
(d) Movement of chocolate in your intestine
Solution:
(a) V
(b) IV
(c) V
(d) IV

Question 43.
Fill in the blanks.
(a) Lining of blood vessels is made up of _____.
(b) Lining of small intestine is made up of _____.
(c) Lining of kidney tubules is made up of _____.
(d) Epithelial cells with cilia are found in_____ of our body.
Solution:
(a) squamous epithelium
(b) columnar epithelium
(c) cuboidal epithelium
(d) respiratory tract

Question 44.
Water hyacinth floats on water surface. Explain
Solution:
Water hyacinth (Eichhornia crassipes) is a free-floating aquatic plant which possesses aerenchyma in its spongy petiole. Aerenchyma consists of a network of which enclose very large air cavities. These air cavities store gases, making the plant light and help it to float on the surface of water.

Question 45.
Which structure protects the plant body against the invasion of parasites?
Solution:
Epidermis is a layer of parenchymatous cells that forms the outermost covering of plant body. Epidermis consists of compactly arranged cells without any intercellular spaces. On the aerial plant parts, it secretes a thick, waxy, water-resistant layer called cuticle on its outer surface. These features .make the epidermis protective against loss of water, mechanical injury and the invasion of parasites.

Question 46.
Fill in the blanks.
(a) Cork cells possess _____ on their walls that makes them impervious to gases and water.
(b) _____ have tubular cells with perforated walls and are living in nature.
(c) Bone possesses a hard matrix composed of _____and _____.
Solution:
(a) suberin
(b) Sieve tubes
(c) inorganic, organic substances

Question 47.
Why is epidermis important for the plants?
Solution:
Epiderms is important for the plants as it performs the following important functions :
(i) It protects the internal tissues from mechanical injuries.
(ii) It acts as a water-resistant layer and checks loss of water by transpiration.
(iii) It protects the plant against invasion of parasitic microorganisms.
(iv) It bears stomata on leaves and on young stems, which help in exchange of gases during photosynthesis and respiration. Stomata also act as sites of transpiration.
(v) Root hairs arising from the epidermis of roots help in absorption of water and minerals from the soil.

Question 48.
Fill in the blanks.
(a) ______ are forms of complex tissue.
(b) ______ have guard cells.
(c) Cells of cork contain a chemical called ______.
(d) Husk of coconut is made of ______ tissue.
(e) ______ gives flexibility to plants.
(f) ______ and ______ are both conducting tissues.
(g) Xylem transports ______ and ______ from soil.
(h) Phloem transports ______ from ______ to other parts of the plant.
Solution:
(a) Xylem and phloem
(b) Stomata
(c) suberin
(d) sclerenchyma
(e) Collenchyma
(f) Xylem; phloem
(g) water; minerals
(h) food; leaves

Long Answer Type Questions

Question 49.
Differentiate between sclerenchyma and parenchyma tissues. Draw well labelled diagrams.
Solution:
Differences between parenchyma and sclerenchyma are as follows:

Question 50.
Describe the structure and function of different types of epithelial tissues. Draw diagram of each type of epithelial tissue.
Solution:
Types of Epithelial Tissue: Depending upon the shape and function of the constituent cells, epithelial tissues are of following types:

• Squamous (cells flattened)
• Columnar (cells tall, columnar or pillar¬like)
• Cuboidal (cells cube-like)
• Ciliated (cells with cilia)
• Glandular (cells secretory in nature)
• Stratified (cells many layered)

Squamous epithelium: The cells in this epithelium are extremely thin and flat and are arranged edge to edge forming a delicate lining or covering. It forms the lining of cavities of ducts and blood vessels, lines the chambers of the heart, covers the skin, and lining of the mouth. It also lines pharynx, oesophagus, anal canal, vagina and lower part of urethra. It provides protection to the underlying parts against abrasion (mechanical injury) and entry of germs or chemicals. It also helps in excretion, gas exchange and secretion of coelomic fluid.
Columnar epithelium: This epithelium consists of cells which are much longer than broad; and look like a column. It forms the lining of stomach and intestines; also found in salivary glands in the mouth, sweat glands and oil glands of the skin. It also lines mammary gland ducts and parts of urethra. It helps in protection, absorption and secretion. Columnar epithelium of intestine is specialised for the absorption of water and digested food.
Cuboidal epithelium: Cells are as long as broad and appear cube-like; a centrally located nucleus is present. The cuboidal epithelium * lines the small salivary ducts, pancreatic ducts, sweat glands, salivary glands and thyroid glands. It also covers the ovaries and lines the sperm-producing tubules. It helps in protection, secretion, absorption, excretion and gamete formation.
Ciliated epithelium: This epithelium, usually consisting of cuboidal or columnar cells, has numerous, thin, delicate, hair-like projections called cilia arising from the outer free surface of the cells. It is found lining the wind-pipe (trachea), kidney tubules, oviducts (Fallopian tubes) and ventricles of the brain. This epithelium helps in the movement of mucus, urine, eggs, sperms and cerebrospinal fluid in a particular direction.
Glandular epithelium: This epithelium consists of columnar cells modified to secrete chemicals. It lines the glands such as gastric glands, pancreatic lobules, intestinal glands, etc.
Stratified epithelium: This is a compound epithelium in which cells are arranged in many layers one above the other. It is found in places where there is much wear and tear, such as the epidermis of skin, lining of the mouth cavity.

Question 51.
Draw well labelled diagrams of various types of muscles found in human body.
Solution:
The three main types of muscular tissues found in human body are :
(i) Skeletal (striated) muscle tissue
(ii) Smooth (Non striated) muscle tissue
(iii) Cardiac muscle tissue.
The well labelled diagrams of these tissues are as follows:

Question 52.
Give reasons for:
(a) Meristematic cells have a prominent nucleus and dense cytoplasm but they lack vacuole.
(b) Intercellular spaces are absent in sclerenchymatous tissues.
(c) We get a crunchy and granular feeling, when we chew pear fruit.
(d) Branches of a tree move and bend freely in high wind velocity.
(e) It is difficult to pull out the husk of a coconut tree.
Solution:
(a) Meristematic cells have a prominent nucleus and dense cytoplasm because they are metabolically highly active and are in continuous state of division. Meristematic cells lack vacuole because they do not store food material, waste material, sap etc.
(b) Sclerenchyma cells have lignified cell walls which makes them compact and leaves no intercellular spaces.
(c) Pear fruit contains sclerenchymatous stone cells or sclereids which provide gritty texture to the fruit. Thus, when we chew pear fruit, we get a crunchy and granular feeling.
(d) Collenchyma tissue present in the branches of a tree provides flexibility to them and allows their easy bending without breaking. Thus the branches move and bend freely in high wind velocity.
(e) The husk of a coconut is made up of sclerenchymatous fibres which consist of compactly arranged cells with thick lignified cell walls and no intercellular spaces. So, they are tightly joined together. Thus, it is difficult to pull out the husk of a coconut.

Question 53.
List the characteristics of cork. How are they formed? Mention their role.
Solution:
Cork covers the old stems of woody trees. Characteristics of cork are as follows :
(i) Cells of cork are dead at maturity.
(ii) These cells are compactly arranged.
(iii) Cells do not possess intercellular spaces.
(iv) Cells possess a chemical substance suberin in their walls.
(v) They are several layers thick.
(vi) Cork is impervious to gases and water.
As plants grow older, a strip of secondary lateral meristem (called cork cambium) develops in the cortical region. It cuts cells towards both outer and inner sides. Gradually, this secondary tissue replaces the epidermal layer of the stem. This forms the several layer thick cork.
Role of cork is as follows:
(i) It protects the internal tissues from mechanical injury and from parasitic attack.
(ii) It contains small pores (called lenticels) for gaseous exchange.
(iii) It provides mechanical strength.

Question 54.
Why are xylem and phloem called complex tissues? How are they different from one other?
Solution:
Both xylem and phloem consist of more than one type of cells, which coordinate to perform a common function. Therefore, they are called complex tissues. Differences between xylem and phloem are:

Question 55.
(a) Differentiate between meristematic and permanent tissues in plants.
(b) Define the process of differentiation.
(c) Name any two simple and two complex permanent tissues in plants/
Solution:
(a) Differences between meristematic and permanent tissues are :

(b) Differentiation can be defined as the phenomenon of transformation of unspecialised cells into specialised cells by the loss of ability to divide and by taking up permanent shape, size, structure and function.
(c) Simple permanent tissues in plants are parenchyma, collenchyma and sclerenchyma. Complex permanent tissues in plants are xylem and phloem.

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CBSE Class 7 Science Notes Chapter 16 Water: A Precious Resource Pdf free download is part of Class 7 Science Notes for Quick Revision. Here we have given NCERT Class 7 Science Notes Chapter 16 Water: A Precious Resource.

CBSE Class 7 Science Notes Chapter 16 Water: A Precious Resource

Water is one of the most common and useful substances around us. Water is essential for the existence of all forms of life.
After knowing the importance of water, awareness is being created by different organisations of the world. 22nd March is celebrated as World Water Day to attract the attention of everybody towards the importance of conserving water. The year 2003 was recognised as ‘International year of freshwater’.

By doing such activities, we spread the message of conservation of natural resources of water and make people understand that there will be no life without water on the earth. We also believe that “if you have water, you can think of the future”. Before we discuss why water is getting scarce, we must know how much water is available for use on our planet.

Water Available for Use
If we take a picture of earth from outer space, it appears blue because of presence of water in the form of sea and ocean. About 71% of surface of the earth is covered with water. Of the total water present on earth, 97.4% is in the seas and oceans but it is not fit for human consumption. Freshwater in a usable form is present in just a small fraction of all water present on the earth.
Most of us assume that there is plenty of water all over the earth. But infact this all water is not suitable for human consumption, not even fit for plants and other forms of life.

Different Forms of Water
Water exists in three forms. These three forms of water are as follows:

• Snow or ice (solid) exists on the earth in the form of ice caps at the poles of the earth, glaciers and snow covered mountains. These are the main sources of water on earth.
• Water (liquid) is present in oceans, lakes, rivers and even
  underground water in the earth’s upper layers.
• Clouds (gas) are found in the form of water vapour present in the atmosphere. On condensation, it turns into droplets and precipitates on earth’s surface in the form of rain.

The continuous recycling of these forms of water takes place and the amount of water on the earth is maintained of constant. Most of the urban areas have a system of water supply whereas underdeveloped/undeveloped areas depend on resources like rivers, lakes, ponds, handpumps, etc.

Groundwater as an Important Source of Water
The wells, tubewells and handpumps are the main sources of water for many people. The water in these sources is the groundwater. It is the upper level of underground water which occupies all the spaces in the soil and rocks and form a water table as shown in the figure below:

The upper limit of groundwater is called water table. It represents the depth of water filled area at a given place. The water table rises and falls depending upon the amount of rainwater that seeps into the groundwater and how much groundwater is drawn out for irrigation and industry. The seeping down of rainwater into the groundwater is called infiltration. The groundwater thus gets recharged by this process.

At some places, the groundwater is stored between layers of hard rock below the water table. This is aquifer which contains the groundwater usable by tubewells and handpumps. These sources however, have limited sources of water and may get exhausted if used excessively.

Depletion of Water Table
Water drawn from underground water gets replenished by seepage of rainwater. The water table does not get affected as long as we draw the same amount of water as is replenished by natural resources like rain.

However, there is a number of factors which cause depletion of water table at a very fast rate which is really a matter of concern for every one of us. Increase in population, industrial and agricultural activities are some common factors affecting water table. Scanty rainfall, deforestation and decrease in the effective area for seepage of water may also deplete the water table.

Increasing Population
As our population increases, we need more water for drinking, washing, cooking and cleaning. We also need more number of houses, offices, shops and roads. This means more construction work and construction itself uses lots of water itself. Most of the time, it is the groundwater. Besides this, there is less open area which can seep in the rain water into the ground.
So, rise in population also increases use of water. This results in depletion of groundwater level to alarmingly low levels (in many cities).

Increased Industrialisation
Water is used by all industries. Almost everything that we use needs water somewhere in its production process. The number of industries is increasing continuously. Most of the water used in the industries is drawn from groundwater. This results in depletion of water.

Agricultural Activities
More food is needed to meet the requirement as there is an increase in population. This puts more pressure to the agriculture practices. In our country, farmers depend on rain, canal water or groundwater for irrigation. Canals are found only at a few places. Since rain is often erratic, canals also suffer frequently from lack of water. Therefore, farmers have to use groundwater for irrigation. This results in depletion of groundwater.

Deforestation
Large scale deforestation has occurred to accommodate the growing population to grow food for them and to provide space for industries. Overgrazing by our animals has also destroyed large amount of vegetation. The green coverage of vegetation slows down the flow of water on land and increases the absorption of water by the soil. Cutting down of trees and vegetation, therefore interferes with the natural processes by which seepage takes place and the groundwater is recharged and causes depletion of water.

Distribution of Water
The distribution of water over the globe is quite uneven due to the number of factors. Some places have a good amount of rain. On the other hand, these are deserts which have scanty rainfall. Some regions have excessive rains which cause floods while some others have very little rainfall which causes drought. India is a vast country and the rainfall is not the same everywhere. Therefore, some regions in our country may have floods while others may suffer from droughts at the same time.

Water Resources in India
India receives a lot of precipitation (rain and snow) in comparison to the rest of the world. The average annual precipitation in India is 1170 mm as compared to the world’s average of 700 mm. The rain map of India showing average rainfall in the different parts of our country.

Note:
1. Government of India, Copyright 2007.
2. Based upon Survey of India map with the permission of the Surveyor General of India.
3. The territorial waters of India extend into the sea to a distance of twelve nautical miles measured from the appropriate baseline.
4. The external boundaries and coastlines of India agree with the Record/Master Copy certified by Survey of India.

Water Management
It is the activity of planning, developing, distribution and managing the optimum use of water resources. It is a subset of water cycle management. Water supply pipes leaking and a lot of water gushing out of the pipes are the wastage of water. It is the responsibility of the civic authorities to prevent such wastage of precious water. Mismanagement or wastage may also take place at the level of individuals also. All of us knowingly or unknowingly waste water, we should also take care for it. Some of the steps which can be taken for the proper management of water are given below:

1. Rainwater harvesting
2. Bawris
3. Drip irrigation

1. Rainwater Harvesting
Most of the rainwater just flows away. This can be skillfully used to recharge the groundwater. The modern buildings of schools, offices, homes can install a rainwater harvesting system, so as to store rainwater in their own premises for future use.

A Case Study
Bhujpur in the Kutch area of Gujarat has a very erratic rainfall. The only source of freshwater lies underground because rivers in this area do not have water throughout the year. Over the years, demand for water has grown. As a result, the water table has gone down alarmingly.
In 1989, the villagers along with a non-governmental organisation, decided to harvest rainwater.
Eighteen chech-dams were built on Ruhmavati river and its tributaries where water percolates through the soil and recharge the aquifers. ^ According to farmers, the wells have water now and the water that flowed into the sea and was wasted has become available for irrigation.

2. Bawris
The bawris is age old method of collecting water. These structures are still found in old buildings, palaces and forts. With time, the bawris fell into disuse and garbage started piling in these reservoirs. However, because of the acute shortage of water, the bawris are being revived. Today the situation is that inspite of scanty rains those places are managing their water needs well.

3. Drip Irrigation
It is a method of watering plants by use of narrow tubings which deliver water directly to the base of a plant. This minimises wastage of water. The mechanism of drip irrigation is shown in the figure given below:

Role for Saving Water
You can be a leader to show people about water management skills. If any pipeline and tap water is leaking there, immediately report to authorities like ‘JAL BOARD’ (in Delhi) to prevent water loss. Educate people about water wise habits which can be developed gradually and will last life long once developed.

Water-wise Habits

• Turn off the tap while brushing, shaving and washing hand. Open when need. This will check the excess flow of water into drains.
• Use mug and water in the bucket for bathing instead of using showers.
• Mop the floor instead of washing.
• Irrigate potted plants with used water for washing rice and dal in the kitchen while cooking.
• Check no tap or pipe is leaking.

Effect of Water Scarcity on Plants
We grow many plants in pots in our homes. These are called potted plants. The potted plants are watered regularly. If the potted plants are not watered even for a few days, the plants will ‘wilt’ (become limp) and ultimately ‘dry up’. If potted plants are not given water for a considerable time, they will die. Thus, sufficient water is essential for maintaining the life of plants. Plants need water to obtain nutrients from the soil and to make food by the process of photosynthesis.
The various effects of water scarcity on plants are

• Water scarcity will affect nutrient uptake from soil by the plants.
• The rate of photosynthesis will decline, so oxygen evolved will be less.
• Rate of transpiration will also decline, so water vapours released in the atmosphere by transpiration will be less, it will disturb the water cycle.

So, in brief, we can say the shortage of water will lead to a shortage of food, shortage of oxygen and shortage of rain also.

We hope the given CBSE Class 7 Science Notes Chapter 16 Water: A Precious Resource Pdf free download will help you. If you have any query regarding NCERT Class 7 Science Notes Chapter 16 Water: A Precious Resource, drop a comment below and we will get back to you at the earliest.

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CBSE Class 7 Science Notes Chapter 17 Forests: Our Lifeline Pdf free download is part of Class 7 Science Notes for Quick Revision. Here we have given NCERT Class 7 Science Notes Chapter 17 Forests: Our Lifeline.

CBSE Class 7 Science Notes Chapter 17 Forests: Our Lifeline

In ancient times, we used to live in forests. It met all our requirements for leading a normal life at that time. Now-a-days, we live in cities and towns far off from forests, so we really do not know the importance of forests in our life. It is a natural renewable resource a habitat (home) to many forms of wildlife like bear, bison, jackal, deer, porcupine, elephant, etc.

Many trees like sal, teak, semal, Sheesham, neem, Palash, fig, khair, amla, bamboo, kachnar and many others are also found in the forests. The forest also contains insects, butterflies, honeybees and birds which help in palliation in the flowering plants of the forest in pollination.

Structure of a Forest
The plants (trees, shrubs and herbs) make different layers in the forest which are described below:
1. Canopy
The uppermost branches and leaves of tall trees which act as a roof over the forest ground is called canopy. It is the highest layer of vegetation in the forest. The branch part of a tree above the stem is known as the crown of the tree.

2. Understorey
The different horizontal layers formed due to different types of crowns in the forest is called understorey. The constituents of understorey can be described as follows:

(i) Top layer It constitutes the gaint and tall trees followed by shrubs and tall grasses.
(ii) Shrub layer It has many shrubs and bushes of approximately 1-2 metres of height from the forest floor. It makes dense layer at some places of forest where enough sunlight is present.
(iii) Herb layer Just below the shrub layer occurs the herb layer of plants. It is the lowest layer of vegetation in the forest (having leafy plants). Most of the plants in herb layer have short lifespan.
(iv) Forest floor Plants found here are as small as mosses, liverworts, lichens. It has many kinds of insects, worms, toad stool, etc. Most of the forest floor is covered with dead and decaying plant matter, and animal waste.

Components of the Forest
The living organisms found in the forest are plants, animals, decomposers and scavengers. The non-living environment of the forest provides nutrients, water and carbon dioxide for the growth of the plants.
1. Plants
Green plants are living organisms also called autotrophs as they produce food by photosynthesis (by absorbing nutrients water from soil, CO2 from air and sunlight as energy source). They provide food to all living organisms which live in the forest. They are called producers (of food).

2. Animals
Forests have many animals and they are called consumers (of food). The animals which eat only plants/their parts are called herbivores (herb eating) whereas flesh-eating animals are called carnivores. All animals are called heterotrophs because they depend on other organisms for food.

3. Decomposers
Mostly these organisms are microorganisms like bacteria and fungi. They feed on dead plants and animals and thus are called saprotrophs. These organisms are also called decomposers as they breakdown dead parts of plants and dead bodies of animals into simple substances. They play a very important role in sustaining the forests.

4. Scavengers
Those animals which eat dead animals are called scavengers, e.g. vultures, crows, jackals, hyena, some insects (ants, beetles, termites, woodlice, maggots, millipedes and earthworms), etc. Scavengers are the cleaning agents of our environment. But these are not decomposers as they do not breakdown complex dead organic matter into simple ones.

Importance of Forests
The forests provide us with a large number of products. They also purify air and water quality and maintain soil moisture and climate. So, they are called lifeline.

1. Forests Provide Many Useful Products
The various things which are obtained from the forests are called forest products. Forests give us a large number of useful products. Some of the important products which we get from the forests are wood, honey, gum, sealing wax (or lac), catechu (kattha), fruits, oils, spices, natural rubber, cork, dyes, medicinal plants and fodder for cattle. Perhaps the most important product obtained from forests is the wood (which is obtained by cutting down the forest trees). The wood obtained from forests is used for a large number of purposes in our day-to-day life.

2. Forests Maintain Balance between Oxygen and Carbon Dioxide
Plants in the forest release oxygen during photosynthesis. This provides all animals including us with oxygen to breathe and helps to maintain the ratio of oxygen to carbon dioxide in the atmosphere. That is why, forests are called green lungs.

If the amount of carbon dioxide increases in the atmosphere, it would result in an increase in earth’s temperature. Plants in the forest intake carbon dioxide from the atmosphere during photosynthesis. Hence, they help to maintain the right amount of carbon dioxide in the atmosphere.

3. Forests Maintain Water Cycle
The forest trees suck water from the soil through their roots and release water vapour into the air through transpiration. This water vapour helps in the formation of clouds and bring rain on the earth. Thus, forests bring sufficient rainfall on the earth. In fact, about half the rain which falls in forest areas comes from the transpiration of forest trees themselves. In this way, forests help in maintaining a perfect water cycle in nature and meet our freshwater requirements.

4. Forests Prevent Occurrence of Flood
The forest acts as a natural absorber of rainwater and allows it to seep. It helps to maintain the water table throughout the year. Forests not only help in controlling floods but also help to maintain the flow of water in the streams so that we get a steady supply of water.

On the other hand, if trees are not present, rain hits the ground directly and may flood the area around it. Heavy rain may also damage the soil. Roots of trees normally bind the soil together, but in their absence, the soil is washed away or eroded.
The different kinds of plants grow together in the forest making different levels of layers and habitat for wild animals. In the absence of plants/trees, the soil will not hold water which will cause flood and erosion.

5. Forests Provide Habitat for Wildlife
The different types of vegetation present in a forest provide food and shelter to animals, birds and insects which live in the forest. This makes a food chain.

Food chain
Food chain can be defined as a sequence of living organisms in which one organism feeds on another.
A typical chain in grassland is: grass → deer → lion
A typical food chain in a pond is: algae → small fish → large fish

Flow of Energy in a Food Chain
The sun is the ultimate source of energy for everything on the planet. Green plants or producers are able to harness the energy of the sun to make food. In a food Flow ener0y in food chain chain, energy from plants (producers) is passed on from one organism to another. From the producers, the energy goes to primary consumers (herbivores) and is then passed on to secondary consumers (carnivores). Thus, producers are always at the beginning of the food chain.

Dynamic Living Entity
By harbouring greater variety of plants, the forest provides great opportunities of food and habitat for the herbivores. Larger number of herbivores means increased availability of food for a variety of carnivores. The wide variety of animals helps the forest to regenerate and grow. Decomposers help in maintaining the supply of nutrients to the growing plants in the forest. Therefore, the forest is a dynamic living entity. There is a continuous interaction between soil, water, air, plants and animals in a forest.

6. Forests can Regenerate on their Own
The dead parts of trees and plants, dead animals and animal wastes (like animal dung or droppings) keep on collecting on the forest floor. Decomposers (fungi and bacteria) degrade them into simple organic substances which are usable by plants in the form of humus. The hummus makes the forest soil fertile by providing the nutrients. The animals, birds of forests, wind and water disperse the seeds of trees and plants on the forest soil. These seeds obtain nutrients from the soil and germinate to form seedlings and ultimately grow to form the forest vegetation.

Forest Conservation
Paper is made from wood pulp that is produced from the wood of forest trees. So, to make paper, many trees have to be cut down from the forests. If all of us keep on collecting old newspapers, magazines, books, notebooks, etc., and send them to paper mills for recycling through a junk dealer (kabaddi wala), we will be able to save many forest trees from being cut down.
Some of the other ways to conserve forests are also given below:

• Excessive cutting down of forest trees should not be allowed by the government to conserve forests.
• More trees should be planted in the forest in place of cut down trees to conserve forests.
• Paper products such as old newspapers, magazines, books, notebooks, etc., should be recycled to conserve forests.

A large number of forest trees are being cut down every day to meet the various demands of the increasing population. This is called deforestation. Following are the consequence if forests disappear:

• Increase of the earth’s temperature If there are no trees and plants, their will be no photosynthesis. So, no C02 of the atmosphere will be used. This will increase the level of C02, resulting in the increase of earth’s temperature.
• No food and shelter to wildlife In the absence of trees, plants and animals will not get food and shelter. So, this will disrupt the whole cycle of life and gradually life might disappear from the land area of the earth.
• There will be more floods The trees plant roots help in holding the soil during rains and also soil is able to hold water. In the absence of trees, the soil will not hold water which will cause floods.
• Deforestation endanger the environment The continuous deforestation is threatening the different form of life including human beings. So, there is necessity to think and set to conserve forests. Natural calamities like floods, cyclones, hail forms are more in the absence of trees and forest. People become homeless when such disaster occurs.

We hope the given CBSE Class 7 Science Notes Chapter 17 Forests: Our Lifeline Pdf free download will help you. If you have any query regarding NCERT Class 7 Science Notes Chapter 17 Forests: Our Lifeline, drop a comment below and we will get back to you at the earliest.

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CBSE Class 7 Science Notes Chapter 18 Waste Water Story Pdf free download is part of Class 7 Science Notes for Quick Revision. Here we have given NCERT Class 7 Science Notes Chapter 18 Waste Water Story.

CBSE Class 7 Science Notes Chapter 18 Waste Water Story

Water is an elixir of life. We all use water and in that process of using, we make it dirty. The water rich in a lather, mixed with oil and other pollutants that go down the drains from sinks, showers, toilets, laundries is dirty. It is called wastewater.

We use water every day for drinking, bathing, washing clothes, cooking food, washing utensils, flushing toilets, mopping the floors, etc. We cannot think of our life without water. We use lots of water daily which is passed on to the drainage system every day.

Water, Our Lifeline
Water is needed by all forms of life. Clean water is a basic need of human beings. Unfortunately, clean water is not available to a large segment of human populations.

The water which is unfit for human consumption becomes the source of many water-borne diseases which ultimately lead to loss ( of human life. It is estimated that one billion human beings do not get safe drinking water. So, realising the urgency we celebrate 22nd March as World Water Day to bring awareness amongst people for safe water, fit for human consumption.
Thus, the water is cleaned by removing pollutants before it enters a waterbody or is reused. This process of wastewater treatment is commonly known as sewage treatment which takes place in several steps as discussed later.

On the World Water Day, i.e. 22 March 2005, the General Assembly of the United Nations proclaimed the period 2005-2015 as the International Decade for action on Water for Life. All efforts made during this decade aim to reduce by half the number of people who do not have access to safe drinking water.

Sewage
It is wastewater released by homes, industries agricultural fields and other human activities. It also includes rainwater that has run down the street during a storm or heavy rain and it is liquid waste. Most of its water has dissolved and suspended impurities called contaminants.

Composition of Sewage
The following components make the sewage:

• The organic impurities present in sewage are human faeces, animal wastes (like animal dung), urea (as urine), oil, fruits and vegetable wastes, pesticides, herbicides, etc.
• The inorganic impurities present in sewage are nitrates, phosphates and metals.
• The nutrients present in sewage are nitrogen and phosphorus.
• The bacteria present in sewage include those bacteria which cause water-borne diseases such as cholera and typhoid.
• The other microbes present in sewage are Protozoa which cause a water-borne disease called dysentery.

Water Freshens Up: An Eventful Journey
In a house (a public building) generally, there are two sets of pipes, i.e. one set of pipes brings clean drinking water into the house and the other set of pipes takes away wastewater (sewage) from houses. For proper sanitation, a well-maintained sewage system is required.

Sewerage System
The pipes which carry away wastewater or sewage from houses and other buildings are buried under the ground. An underground pipe which carries away dirty drainage water and waste matter is called sewer. The provision of drainage at a place by laying sewers under the ground is called sewerage. Actually, sewerage is an underground network of interconnected pipes called sewers that carries the sewage from the place where it is produced to the sewage treatment plants, where it is processed.

Manholes
A manhole is a covered vertical hole in the ground, pavement or road, above the underground sewer pipeline through which a worker can go down up to the sewer pipes for inspection, cleaning, etc. Manholes are provided at every 50-60 m distance in the main sewer pipeline. Manholes are also provided at the junction of two or more sewers and at points where there is a change in the direction of the sewer line.

Treatment of Polluted Water
Perform the following activity. It will help you to understand the processes that take place at the wastewater treatment plant.

Wastewater Treatment Plant (WWTP)
A place where wastewater or sewage from houses and other buildings is brought for processing is called wastewater treatment plant.
Treatment of wastewater involves physical, biological and chemical processes depending on the nature of contaminants.

1. Physical Process (Screening)
The bar screens first remove the large rubbish objects like rags, sticks, cans, polybags, napkins, sanitary towels, etc., from the wastewater.

After passing through the bar screen, wastewater is taken to a tank called grit and sand removal tanks. In this, sand and grit settle down slowly at the bottom of the tank as water passes slowly through this tank. The settled sand and impurities are removed from the tanks from time to time.

2. Biological Process
The first sedimentation tank is sloped towards the centre. Solid like faeces settle at the bottom and is called sludge which is removed by a scraper. Oils and grease float at the surface of the water are removed by a skimmer. The biogas produced (by anaerobic bacteria) in the process can be used as fuel or can be used to produce electricity. Here, water gets cleared of rubbage, oil, grease, etc and we get clarified water which is sent to aeration tank now. In the aeration tank, the watery waste already contains bacteria (aerobic) in it. The compressed air bubbles are passed through this waste to provide 02 to the bacteria to increase bacterial activity which ultimately digests human waste, food waste, soaps and other unwanted and harmful matter still remaining in the wastewater leaving behind fairly pure water.

3. Chemical Process
The water after aeration tank is allowed to stand in a second sedimentation tank. Here, the microbes present get settled at the bottom at the tank in the form of activated sludge which is about 97% water. At this stage, water has very low level of organic matter suspended matter and does not contain many harmful things. It is safe for human consumption but is disinfected by chlorine or ozone before distributing it.

Become an Active Citizen
Waste generation is a natural part of human activity but we can limit the type of waste and quantity of waste produced. Often we have been repelled by an offensive smell. The sight of open drains is disgusting. The situation worsens in the rainy season when the drains start overflowing. We have to wade through the mud pools on the roads. Most unhygienic and unsanitary conditions prevail. Flies, mosquitoes and other insects breed in it.

We should be an enlightened citizen and approach the municipality or the gram panchayat. We should also insist that open drains should be covered. If the sewage of any particular house makes the neighbourhood dirty. We should request them to be more considerate about other’s health.

Note: We should plant Eucalyptus trees all along sewage ponds. These trees absorb all surplus wastewater rapidly and release pure water vapour into the atmosphere.

Better House Keeping Practices
We must minimise and manage waste at our houses before its disposal in the following manner:

• Cooking oil and fats should not be thrown down the drain. They can harden and block the pipes. In an open drain, the fats clog the soil pores reducing its effectiveness in filtering water. Throw oil and fats in the dustbin.
• Used tea leaves, solid food remains, soft toys, cotton, sanitary towels, etc., should also be thrown in the
  dustbin. These wastes choke the drains. They do not allow the free flow of oxygen. This hampers the degradation process.
• The chemicals like paints, solvents, insecticides, medicines and motor oils should not be thrown in drains as they kill helpful microbes which digest the organic waste.

Sanitation and Disease
Contaminated water and poor sanitation practices are the major causes of the number of infectious diseases in our country. Safe sewage disposal facilities are still not available at many cities and villages in India. So, people go to open places and defecate. This causes the increase in insect-vector population which transmit diseases like cholera, typhoid, meningitis, etc.

Untreated human excreta is a health hazard which causes soil pollution and water pollution also. The river water and groundwater are sources of water for drinking for many people. So, the contaminated water can spread many diseases especially water-borne.

Vermi-processing Toilets
In the vermi-processing toilets, human excreta is treated by earthworms in a pit. The earthworms usually eat up all organic matter present in human excrete and turn it into compost. These are tow water use toilets for the safe processing of human.

Alternate Arrangement for Sewage Disposal
Low cost outside the sewage disposal system has been developed to take care of places where there is no sewage system, e.g. rural areas, isolated buildings. These are described below:
(i) Septic tanks: Septic tank is a low-cost onsite sewage disposal system. Septic tanks are suitable where there is no sewerage made. These tanks need cleaning every four to six months.

A septic tank usually consists of a big, covered underground tank made of concrete having an inlet pipe at one end and on outlet pipe at the other end. The toilet seat is connected to the inlet pipe of the septic tank. The human excreta from the toilet seat enters into the septic tank through the inlet pipe. The solid part of excreta keeps on collecting at the bottom of the septic tank in the form of a sludge whereas watery waste remains above it.

The anaerobic bacteria breakdown most of the solid organic matter present in human excreta due to which the volume of solid waste is reduced too much. The digested solid waste keeps on depositing at the bottom of septic tank. The watery waste is also cleaned by anaerobic bacteria. The excess water goes out of the septic tank through the outlet pipe and get absorbed in soil.

(ii) Composting pits: These are self-sustained human waste disposal units which is not connected to a sewer line or a septic tank. A composting toilet breaks down and dehydrates human waste to compost.

(iii) Chemical toilets: These toilets have limited storage capacity for human waste and need to be emptied periodically. These are the toilets which use chemically treated reservoir located just below the toilet seats. The chemicals reduce the foul smell coming out of human excrete and carry out partial disinfection of human waste.

Sanitation at Public Places
In our country, fairs are organised periodically. A large number of people participate in them. In the same way, railway stations, bus depots, airports, hospitals are very busy places. Thousands of people visit them daily which generate large amount of waste. It must be disposed of properly otherwise epidemics could break out. The government has laid down certain standards of sanitation but unfortunately, they are not strictly enforced. We should not scatter litter anywhere. If there is no dustbin in sight, we should carry the litter at home and throw it in the dustbin.

Conclusion
We all have a role to play in keeping our environment clean and healthy. We must realise our responsibility in maintaining the water sources in a healthy state. Adopting good sanitation practices should be our way of life. As an agent of change your individual initiative will make a great difference. Influence others with your energy ideas and optimum, A lot con be done if people work together. There is great power in collective action.
As an active citizen, we have many responsibilities regarding sanitation. These can be listed as follows:

• To ensure that our surroundings are clean.
• To ensure that the sewerage system in our house is properly managed.
• If any leakage or an open drain in the sewerage system is present, then it should be reported to the municipality or the gram panchayats to insist that the open drain must be covered properly and several air and water-borne diseases can be prevented.

Note: Mahatma Gandhi said, ‘No one needs to wait for anyone else to adopt a humane and enlightened course of action’.

We hope the given CBSE Class 7 Science Notes Chapter 18 Waste Water Story Pdf free download will help you. If you have any query regarding NCERT Class 7 Science Notes Chapter 18 Waste Water Story, drop a comment below and we will get back to you at the earliest.

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CBSE Class 7 Hindi Grammar वर्तनी Pdf free download is part of NCERT Solutions for Class 7 Hindi. Here we have given NCERT Class 7 Hindi Grammar वर्तनी.

CBSE Class 7 Hindi Grammar वर्तनी

भारत एक अलग-अलग प्रांतीय देश है। विविध प्रांतों के लोग रहते हैं, जहाँ अलग-अलग प्रकार की भाषाओं और बोलियों का प्रयोग किया जाता है, जिसका उच्चारण भी क्षेत्रीयता के प्रभाव के कारण अलग-अलग होता है। इससे बचने के लिए उच्चारण में सावधानी बरतना आवश्यक है। वर्तनी की सामान्य अशुधियाँ और उसका निराकरण।

1. स्वर की अशुधियाँ

2. अनुस्वार और अनुनासिक की अशुधियाँ

3. विसर्ग की अशुधियाँ

4. व्यंजन की अशुधियाँ

5. ण, न, इ की अशुधियाँ

श, ष, से के प्रयोग की अशुधियाँ

र, ड, डु, ढ़ की अशुधियाँ

पंचमाक्षर (ड, ञ, ण, न, म) के प्रयोग की अशुधियाँ

क्ष और छ की अशुधियाँ

रू तथा ि की अशुद्धियाँ

बहुविकल्पी प्रश्न

1. निम्नलिखित शब्दों में से शुद्ध शब्दों को छाँटकर उनके आगे सही का चिह्न लगाइए।
(क) (i) त्यौहार
(ii) त्योहार
(iii) तियोहार
(iv) तयोहार

(ख) (i) दवाईया
(ii) दवाईयाँ
(iii) दवाइयाँ
(iv) दवाइयाँ

(ग) (i) स्वास्थ्य
(ii) स्वास्थ्य
(iii) सवास्थ्य
(iv) स्वासथ्य

(घ) (i) कवयित्री
(ii) कवियित्री
(iii) कवीयित्री
(iv) कवीयित्रि

(ङ) (i) उज्ज्वल
(ii) उज्जवल
(iii) उज्जल
(iv) उजजवल

(च) (i) सनयास
(ii) सन्यास
(iii) संन्यास
(iv) संनयास

(छ) (i) पंडित
(ii) पन्डित
(iii) पनडित
(iv) पनडत

(ज) (i) दुकान
(ii) दोकान
(iii) दूकान
(iv) दुकोन

उत्तर-
(क) (ii)
(ख) (iii)
(ग) (ii)
(घ) (i)
(ङ) (i)
(च) (iii)
(छ) (i)
(ज) (i)

We hope the given CBSE Class 7 Hindi Grammar वर्तनी will help you. If you have any query regarding CBSE Class 7 Hindi Grammar वर्तनी, drop a comment below and we will get back to you at the earliest.

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Informatics Practices Class 12 Important Questions Chapter 10 Fundamentals of Database is part of Informatics Practices Class 12 Important Questions. Here we have given Informatics Practices Class 12 Important Questions Chapter 10 Fundamentals of Database.

Informatics Practices Class 12 Important Questions Chapter 10 Fundamentals of Database

1 Mark Questions

Question 1.
Write two examples of DML commands to SQL. (All India 2014C)
Answer:
Two examples of DML commands are:
SELECT, INSERT

Question 2.
When using the LIKE clause, which wildcard symbol represents any sequence of none, one or more characters? (All India 2014c)
Answer:
The % wildcard symbol is used in LIKE clause to represent any sequence of none, one or more characters.

Question 3.
Write the UPDATE statement in MySQL to increase commission by 100.00 in the “Commission” column in the ‘EMP’ table. (All India 2014C)
Answer:
UPDATE Emp
SET Commission = Commission +100;

Question 4.
Rewrite the following SQL statement after correcting the error(s). Underline the corrections made. (All India 2014C)

INSERT IN STUDENT(RNO, MARKS) 
VALUEC5, 78.5);

Answer:

INSERT INTO STUDENT (RNO, MARKS) 
VALUES (5, 78.5);

Question 5.
What happens when auto-commit is set on? (Delhi 2014)
Answer:
When AUTOCOMMIT is set on then we do not need to start a transaction explicity using a BEGIN command but every statement is treated as an independent transaction and will COMMIT automatically immediate after its completion.

Question 6.
Table ‘CLUB’ has 4 rows and 3 columns. Table ‘MEMBER’ has 2 rows and 5 columns. What will be the cardinality of the Cartesian product of them? (Delhi 2014)
Answer:
The cardinality of the cartesian product of Table ‘CLUB’ and Table ‘MEMBER’ = 8.

Question 7.
Distinguish between ALTER TABLE and UPDATE commands of MySQL. (All India 2014)
Answer:
ALTER TABLE command is a DDL (Data Definition Language) statement which is used to modify the table structure. On the other hand UPDATE command is a DML (Data Manipulation Language) statement which is used to modify the data stored in a table.

Question 8.
Mention two categories in which MySQL commands are broadly classified. (All India 2014)
Answer:
Two categories of Mysql commands are:

• DDL (Data Definition Language)
• DML (Data Manipulation Language)

Question 9.
Give two characteristics of Primary Key. (All India 2014)
Answer:
Two characteristics of Primary Key are:

• All the values in the Primary Key field are unique.
• Does not allow NULL values.

Question 10.
Write two examples of DBMS software. (Delhi 2014)
Answer:
Two examples of DBMS Software are:

• MySQL
• Oracle

Question 11.
Write SQL command to create a SAVEPOINT called All (Delhi 2013)
Answer:

Create Table CLASS (Rollno INTEGER, Name VARCHAR(20));
INSERT INTO CLASS(10, ‘CS’);
SAVEPOINT Al;

Question 12.
Define a foreign key with reference to RDBMS. (Delhi 2013)
Answer:
Foreign Key It is primary key of another table. It’s used to join two tables. Name of the foreign key and the primary key may or may not be same but their data type has to be same.

Question 13.
Write the command to display the list of existing databases. (Delhi 2012)
Answer:
The command to display list of existing databases are as follows:

Show databases;

Question 14.
Mr. William wants to remove all the rows from INVENTORY table to release the storage space, but he does not want to remove the structure of the table. What MySQL statement should be used? (Delhi 2012)
Answer:
The command to delete all rows from the Inventory table without deleting the structure of the table will be as follows:

DELETE FROM INVENTORY;

Question 15.
Write MySQL command to open an existing database. (All India 2012)
Answer:
The command to open an existing database is as follows:

USE database_name;

Question 16.
Give one difference between COMMIT and ROLLBACK commands used in MySQL. (HOTS; Delhi 2012; All India 2012)
Answer:
The COMMIT command is used to save the changes made during the execution of a transaction permanentely on the disk. After executing the COMMIT command, we cannot undo or cancel the changes made thereupon. Whereas the ROLLBACK command is used to undo the changes made during the execution of a transaction.

Question 17.
Write MySQL command, which will be used to open an already existing database “LIBRARY”. (All India 2012, Delhi 2011)
Answer:
The SQL command to open an already existing database LIBRARY will be as follows:

USE LIBRARY;

Question 18.
Differentiate between alternate key and candidate key (All India2011)
Answer:
The attribute or a combination of attributes that have unique values for each record known as candidate key whereas a candidate key that is not the primary key is known as an alternate key.

Question 19.
In MySQL Reena and Zebi are getting the following output of SELECT statement on a table EMPLOYEE (HOTS; Delhi2011c)

Which keyword has Zebi used with a select statement to get the above output?
Answer:
Zebi has used DISTINCT clause with the SELECT command.

Question 20.
Write MySQL command, which will open an already existing database “CONTACTS (Delhi 2011c)
Answer:
The SQL command to open an already existing database CONTACTS will be as follows:

Use CONTACTS;

Question 21.
Write SQL command used to display the structure of a table. (Delhi 2011c)
Answer:
The command to display the structure of a table is as follows:

DESCRIBE table_name; 
or DESC table_name;

Question 22.
Mr. lames created a table CLIENT with 2 rows and 4 columns. He added 2 more rows to it and deleted one column. What is the Cardinality and Degree of the Table CLIENT?
Answer:
Cardinality = 4
Degree = 3
Cardinality are the number of rows and degree is number of the columns in a table.

2 Marks Questions

Question 23.
(i) If you have not executed the COMMIT command, executing which command will reverse all updates made during the current work session in MySQL?
(ii) What effect does SET AUTOCOMMIT have in transactions? (All India 2014C)
Answer:
(i) ROLLBACK command can only be used to undo transactions.
(ii) Autocommit simply means that each statement in its own transaction which commits immediately. When autocommit is set ON, the SET IMLICITTRANSACTION sets the connection to implicit transaction mode. When set OFF, it returns the connection to autocommit transaction mode.

Question 24.
A table FUN FOOD has 13 rows and 17 columns. What is the cardinality and degree of the table? (All India 2014)
Answer:
Cardinality of FUN FOOD = 13
Degree of FUN FOOD = 17

Question 25.
What happens when “ROLLBACK” command is issued in a transaction process? (All India 2014)
Answer:
When a ROLLBACK command is issued in a transaction process then all the progress made by a transaction process upto that point will be lost i.e. all the changes made by that transaction process are undone.

Question 26.
Gopi Krishna is using a table EMPLOYEE. It has the following columns:
Code, Name, Salary, Dept code He wants to display maximum salary Departmentwise.
He wrote the following command:

SELECT Dept code, Max(Salary)
FROM EMPLOYEE:

But he did not get desired result.
Rewrite the above query with necessary change to help him get the desired output. (Delhi 2014)
Answer:

SELECT Deptcode, Max(Salary)
FROM EMPLOYEE GROUP BY Deptcode;

Question 27.
What is the use of COMMIT statement in SQL? How is it different from ROLLBACK statement? (Delhi 2013C)
Answer:
The use of the COMMIT statement in MySQL is to end your current transaction and make all changes permanent performed in the transaction. ROLLBACK statement roll back the present transaction, which means canceling a transaction’s changes.

Question 28.
Name two categories into which SQL commands may be categorized. Also, give one example of SQL commands in each category. (Delhi 2012)
Answer:
The two categories of SQL commands are as follow:
(i) DDL DDL stands for Data Definition Language. The DDL commands are used to Create, Modify or Destroy the structure of the database objects,
E.g., CREATE TABLE, ALTER TABLE are of this category.

(ii) DML DML stands for Data Manipulation Language. The DML commands are used to insert, display, delete or change data in tables,
E.g.,
SELECT, INSERT, UPDATE, DELETE, etc., commands are of this category.

Question 29.
The Mname Column of a table Members is given below

Based on information, find the output of the following queries

(i) SELECT Mname FROM Members WHERE Mname ' “%\v"; 
(ii) SELECT Mname FROM Members WHERE Mname LIKE "%e%"; (Delhi 2011)

Answer:
The output of given commands will be as follows
(i) Hirav, Rajeev
(ii) Sheetal, Rajeev.

Question 30.
What is the purpose of ALTER TABLE command in MySQL? How it is different from UPDATE commands? (All India 2011)
Answer:
The ALTER TABLE command is used to change the structure of an existing table. It can be used to add a new column, to change the size or type of a column or to remove a column from a table. But update commands cannot effect the table structure.

Question 31.
The Doc_name column of a table HOSPITAL is given below (All India 2011)

Based on information, find the output of the following queries

(i) SELECT Doc_name FROM HOSPITAL WHERE Doc_name LIKE ‘%v’;.
(ii) SELECT Doc_name FROM HOSPITAL WHERE Doc_name LIKE

Answer:
The output of given commands will be as follows:
(i) Sanjeev
(ii) Deepak, Sanjeev.

Question 32.
A table “TRAINS” in a database has degree 3 and cardinality 8. What is the number of rows and columns in it? (Delhi 2011; All India 2011)
Answer:
There will be 8 rows and 3 columns.

Question 33.
Sarthak, a student of class XI created a table “CLASS”. Grade is one of the column of this table. To find the details of students whose Grades have not been entered, he wrote the following MySQL query, which did not give the desired result

SELECT * FROM CLASS 
WHERE GRADE = "NULL”

Help Sarthak to run the query by removing the errors from the query and write the correct query. (Delhi 2011; All India 2011)
Answer:
The correct query is

SELECT * FROM CLASS.
WHERE GRADE IS NULL;

Question 34.
Anurag, a student of class XI created a table “PLAYER SCORE”. Current score is one of the column of this table. To find the details of players whose current score is more than 100, he wrote the following MySQL query, which did not give the desired result

SELECT * FROM PLAYER_SCORE
WHERE Current_score>“100”;

Help Anurag to run the query by removing the errors from the query and write the correct query. ‘
Answer:
As score is a numeric data type, so double quotes are not allowed.

SELECT * FROM PLAYER_SC0RE 
WHERE Current_Score > 100;

Question 35.
Differentiate between COMMIT and SAVEPOINT.
Answer:

Question 36.
Amit, a salesman in an Outlet, created a table TRANSACTIONS an Amount is one of the column of this Table. To find the details of customer whose transaction amount is more than 800, he wrote the following MySQL query, which did not give the desired result:

SELECT * FROM TRANSACTIONS 
WHERE Amount > “800”;

Help Amit to run the query by removing the errors from the query and write the correct query.
Answer:
Correct query is

SELECT * FROM TRANSACTIONS 
WHERE Amount > 800;

Question 37.
Anushka, a salesman in an Outlet, created a table, CUSTOMERS. PhoneNumber is one of the column of this table, which is character type. To find the details of customers whose PhoneNumber is 259624, she wrote the following MySQL query, which did not give the desired result:

SELECT * FROM CUSTOMERS 
WHERE PhoneNumber = 259624;

Help Anushka to run the query by removing the errors from the query and write the correct query.
Answer:
As PhoneNumber is character type so it must be enclosed in single quotes So, correct query is

SELECT * FROM CUSTOMERS 
WHERE PhoneNumber = ‘259624’;

Question 38.
Natasha, a salesgirl in an outlet, created table SUPPLIERS. PhoneNumber is one of the column of this table, which is numeric type. To find the details of customers whose number is 345941, she wrote the following MySQL query, which did not give the desired result:

SELECT * FROM SUPPLIERS 
WHERE PhoneNumber = “345941”;

Answer:
As PhoneNumber is numeric type so it should not be enclosed in double quotes. The correct query is

SELECT * FROM SUPPLIERS 
WHERE PhoneNumber = 345941;

Question 39.
Shammi, a student of class XII created a table FRIENDS. Pincode is one of the column of this table, which is character type. To find the details of friend whose pin code number is 262122, he wrote the following MySQL query, which did not give desired result:

SELECT * FROM FRIENDS 
WHERE PinCode = 262122;

Help Shammi to run the query by removing the errors from the query and write the correct query.
Answer:
The correct query is

SELECT * FROM FRIENDS 
WHERE PinCode = ‘262122’;

4 Marks Questions

Question 40.
In a database BANK, there are two tables with a sample data given below
TABLE EMPLOYEE

TABLE DEPARTMENT

Note:
– EName refers to Employee Name
– DName refers to Department Name
– Dept refers to Department Code
– HOD refers to Employee number (ENO) of the Head of the Department
Write SQL queries for the following:
(i) To display ENo, EName, Salary and corresponding DName of all the employees whose age is between 25 and 35 (both values inclusive).
(ii) To display DName and corresponding EName from the tables DEPARTMENT and EMPLOYEE, (Hint’ HOD of the DEPARTMENT table should be matched with ENo of the EMPLOYEE table for getting the desired result).
(iii) To display EName, Salary, Zone and Income Tax
(Note Income Tax to be calculated as 30% of salary) of all the employees with appropriate column headings. (HOTS; Delhi 2013)
Answer:

(i) SELECT e.ENo,e.EName,e.Salary,d.DName
FROM EMPLOYEE e, DEPARTMENT d 
WHERE e.Dept = d.Dept AND e.Age BETWEEN 25 AND 35;
(ii) SELECT e.EName,d.DName
FROM EMPLOYEE e, DEPARTMENT d 
WHERE e.ENO = d.HOD;
(iii) SELECT EName, Zone, Salary x 0.3 
“Income Tax” FROM EMPLOYEE;

Question 41.
TABLE ITEM

TABLE BRAND

Write MySQL queries for the following
(i) To display ltem_Code, ltem_Name and corresponding Brand_Name of those items, whose Price is between 20000 and 40000 (both values included).
(ii) To display ltem_Code, Price and Brand_Name of the item which has ltem_Name as “Computer”.
(iii) To increase the prices of all the items by 10%.
Answer:

(i) SELECT i. Item_Code,i. Item_Name,
b.Brand_Name FROM ITEM i, BRAND b 
WHERE i .Item_Code = b.Item_code AND 
i.Price BETWEEN 20000 AND 40000;
(ii) SELECT i.Item_Code, Price, 
b.Brand_Name
FROM ITEM i, BRAND b
WHERE i. Item_Code = b. Item_Code
AND i. Item_Name = ‘Computer’;
(iii) UPDATE ITEM
SET Price = Price + (Price*0.1);

Question 42.
TABLE ITEM

TABLE CUSTOMER

Write MySQL queries for the following:
(i) To display the details of Item, whose Price is in the range of 40 and 95 (both values included).
(ii) To display CustomerName, City from table CUSTOMER and ItemName and Price from table ITEM, with their corresponding matching ID.
(iii) To increase the prices of all the Items by 50%. (Delhi 2011)
Answer:

(i) SELECT * FROM ITEM
WHERE Price BETWEEN 40 AND 95;
(ii) SELECT CUSTOMER. CustomerName, 
CUSTOMER.City, ITEM.Item_Name,
ITEM.Price
FROM ITEM, CUSTOMER 
WHERE ITEM.ID = CUSTOMER.ID;
(iii) UPDATE ITEM SET Price = Price +
Price * 0.50;

Question 43.
Create table CUSTOMER as per following Table Instance Chart

Answer:
The SQL command to create a table as per given structure is as follows:

CREATE TABLE CUSTOMER
(Cust ID INTEGER,
Cust_Name VARCHAR(30),
Cust_Add VARCHAR(20),
Pincode INTEGER,
Cust_Phone VARCHARC10));

Question 44.
Create table STUDENT as per following Table Instance Chart

Answer:
The SQL command to create a table as per given structure is as follows:

CREATE TABLE STUDENT
(RolI_No INTEGER,
Name VARCHAR(30),
Address VARCHAR(20),
Pincode INTEGER,
Phone VARCHAR!10));

Question 45.
Write an SQL query to create a table STUDENT with the following structure

Answer:
The SQL command to create a table as per given structure is as follows:

CREATE TABLE STUDENT
(Roll_Number INTEGER,
Name VARCHAR(20),
Stream VARCHAR(IO),
Date_of_Admission Date);

Question 46.
Write an SQL query to create a table CUSTOMER with the following structure

Answer:
The SQL command to create a table as per given structure is as follows:

CREATE TABLE CUSTOMER
(Cust_ID INTEGER,
Cust_Name VARCHAR(20),
Address VARCHAR(20),
Balance DECIMAL);

Question 47.
Write an SQL query to create a table TEACHER with the following structure

Answer:
The SQL command to create a table as per given structure is as follows:

CREATE TABLE TEACHER
(Teacher_ID INTEGER,
Teacher_Name VARCHAR(20), 
Qualification VARCHAR(20), 
Date_of_Appointment DATE);

Question 48.
Write an SQL query to create a table ITEM with the following structure

Answer:
The SQL command to create a table as per given structure is as follows:

CREATE TABLE ITEM
(Item_Code INTEGER,
Item_Name VARCHAR(20),
Unit_Price DECIMAL,
Qty_in_Stock INTEGER);

Question 49.
Write an SQL query to create a table ACCOUNTS with the following structure

Answer:
The SQL command to create a table as per given structure is as follows:

CREATE TABLE ACCOUNTS
(Trans_Date DATE,
Particulars VARCHAR(20),
Debit DECIMAL,
Credit DECIMAL);

Question 50.
Write an SQL query to create a table LIBRARY with the following structure

Answer:
The SQL command to create a table as per given structure is as follows:

CREATE TABLE LIBRARY
(Book_No INTEGER,
Book_name VARCHAR!20),
Category VARCHAR(20),
Price DECIMAL,
Qty INTEGER);

Question 51.
Write an SQL query to create a table LAB with the following structure

Answer:
The SQL command to create a table as per given structure is as follows:

CREATE TABLE LAB
(App ID INTEGER,
App_name VARCHAR (20),
Description VARCHAR(20),
Price DECIMAL,
Qty INTEGER);

Question 52.
Write an SQL query to create a table SPORTS with the following structure

Answer:
The SQL command to create a table as per given structure is as follows:

CREATE TABLE SPORTS
(Item_ID INTEGER,
Item_name VARCHAR(20),
Description VARCHAR(20),
Price DECIMAL,
Qty INTEGER);

We hope the Informatics Practices Class 12 Important Questions Chapter 10 Fundamentals of Database help you. If you have any query regarding Informatics Practices Class 12 Important Questions Chapter 10 Fundamentals of Database, drop a comment below and we will get back to you at the earliest.

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Informatics Practices Class 12 Important Questions Chapter 13 Front-End Interface is part of Informatics Practices Class 12 Important Questions. Here we have given Informatics Practices Class 12 Important Questions Chapter 13 Front-End Interface.

Informatics Practices Class 12 Important Questions Chapter 13 Front-End Interface

1 Mark Questions

Question 1.
Define a user interface.
Answer:
A user interface is a collection of techniques, styles, mechanisms, etc., to establish interaction between user and computer.

Question 2.
Explain the importance of good Graphical User Interface (GUI). (HOTS)
Answer:
A good Graphical User Interface (GUI) is important for user acceptance and success of software. It must be easy to use, yet powerful and capable of performing all the required tasks. When the software and its interface is too complex, the user will not accept it.

Question 3.
What do you understand by a front-end?
Answer:
A front-end is the user interface that interacts with the user and collects information from the user. It provides the user screen for working with the software.

Question 4.
Write names of some basic controls.
Answer:
Some basic controls used in Java NetBeans are JButton, JCheckBox, JList, JRadioButton, etc.

Question 5.
Write the names of controls used in Java NetBeans environment for interactive displays.
Answer:
Some of controls used for interactive displays in Java NetBeans are JColorChooser, JTextPane, JTable, etc.

Question 6.
Write the names of some uneditable information displays.
Answer:
Some uneditable controls for information displays are JLabel, JProgressBar, JToolTip, etc.

Question 7.
Write names of some top-level containers.
Answer:
Some top-level containers used with Java NetBeans are JApplet, JDialog, JFrame, etc.

Question 8.
Write the names of some general purpose containers used in Java NetBeans.
Answer:
Some of the general purpose containers used with Java NetBeans are JPanel, JScrollPane, JSplitPane, etc.

Question 9.
Explain the use of JButton control.
Answer:
The JButton control is used to display a push button on the screen. When during the execution of the program, the user clicks on it, the related action or event starts.

2 Marks Questions

Question 10.
Steve Antony works for HM Academy. He wants to create controls on a form for the following operations. Choose appropriate controls from TextBox, Label, RadioButton, ListBox, ComboBox, CheckBox and
Answer:

Question 11.
Shobit is creating a form for his company. Help her to choose most appropriate controls from ListBox, ComboBox, TextField, TextArea, RadioButton, CheckBox, Label and Command Button for the following entries: (Delhi 2014)
Answer:

• The most appropriate control to select citizenship from a list of countries is JList.
• To allow to input grade out of ‘A’ to ‘D’ the most appropriate control is JRadioButton.
• The most appropriate control in selecting one or many food items is JCheckBox.
• The most appropriate control to allow entering feedback in the form of a paragraph is JTextArea.

Question 12.
Mr. Anurag Das working as Manager in Vivian Enterprises wants to create a form in NetBeans to take various input from user. Choose appropriate controls from Label, TextBox, RadioButton, CheckBox, ListBox, ComboBox and Command Button. Write the most appropriate controls in the third column. (Delhi 2012; All India 2012)
Answer:

Question 13.
Jaina is creating a form for the practical file. Help her to choose most appropriate controls from ListBox, ComboBox, TextField, TextArea, RadioButton, CheckBox, Label and Command Button for the following entries from the user:
(i) A message “Enter Name” in front of a text field.
(ii) An input to choose more than one subjects from a set of given choices.
(iii) An input for entering comments of user.
(iv) An input for accepting the residential area out of rural and urban as option. (Delhi 2011)
Answer:
(i) To display message “Enter Name” in front of a text field, the most appropriate control is JLabel.
(ii) To choose more than one subjects from a set of given choices, the most appropriate command is JList or JComboBox.
(iii) To input comment for the user, the most appropriate control is JTextArea.
(iv) To input the residential area out of rural and urban as option, the most appropriate control is JRadioButton.

Question 14.
Anuja is creating a form for practical file. Help her to choose most appropriate controls from ListBox, ComboBox, TextField, TextArea, RadioButton, CheckBox, Label and Command Button for the following entries from the user
(i) A message “Enter Marks” in front of a text field.
(ii) An input to choose more than one subjects from a set of a given choice.
(iii) An input for entering remarks.
(iv) An input for accepting gender. (All India 2011)
Answer:
(i) The most appropriate control for displaying message “Enter Marks” in front of a text field is JLabel.
(ii) The most appropriate control to choose more than one subjects from a set of given choices is JList or JComboBox.
(iii) The most appropriate control for entering remarks is JTextArea.
(iv) The most appropriate control to accept gender is JRadioButton.

Question 15.
Namita works for a store. She wishes to create controls on a form for the following functions. Which controls should she use? Choose appropriate controls from TextBox, Label, OptionButton, CheckBox, ListBox, ComboBox, CommandButton. (HOTS; Delhi 2011C)
Answer:

Question 16.
Suruchi works for a Shopping Mart. She wants to create controls on a form for the following operations: Choose most appropriate controls out of TextBox, Label, RadioButton, ListBox, ComboBox, CheckBox and CommandButton.
Answer:

Question 17.
Define a front-end of an information system.
Answer:
This is the user interface that the user sees and which is responsible for interacting with the user. The front-end is responsible for receiving user’s queries, requests, etc., and passing it over the back-end. The front-end basically includes graphical user interfaces and the input forms, through which users interact with the system. The interface allows users to issue commands to the system and view the results and in case of the input forms, enter and modify data.

Question 18.
Rohini wants to create an interface for the following. Suggest her the most appropriate command out of TextField, RadioButton, CheckBox, ListBox, TextArea.
(i) To accept name from the user.
(ii) To select Gender (M/F) from the user.
(iii) To display a message “Enter Name” in front of a text field.
(iv) To submit the form.
Answer:
(i) The most appropriate control to accept name from the user is JTextField.
(ii) The most appropriate control to select gender is JRadioButton.
(iii) The most appropriate control to display a message “Enter Name” in front of a text field is J Label.
(iv) The most appropriate control to submit the form is JButton.

Question 19.
Vineet developing one application for Sales Department. He wants to create some controls on a form for the following functions. Choose appropriate controls from TextField, TextArea, Label, RadioButton, CheckBox, ListBox, ComboBox, Button, OptionPane, DialogBox, Menu items.
Answer:

Question 20.
Kritika wants to create an interface for the following. Suggest her the most appropriate command out of TextField, RadioButton, CheckBox, ListBox, TextArea.
(i) To accept Product Name from the user out of given list of options.
(ii) To select Gender (M/F) from the user.
(iii) To select more than one options for hobbies out of given options.
(iv) To clear the fields of the form.
Answer:
(i) The most appropriate control to accept the product name from the user out of a given list of options is JList or JComboBox.
(ii) The most appropriate control to select Gender(M/F) is JRadioButton.
(iii) The most appropriate control to select one or more options for hobbies is JCheckBox.
(iv) The most appropriate control to clear the form is JButton.

Question 21.
Manoj is developing one application for accounting purpose. He wants to create some controls on a form for the following functions. Choose appropriate controls from TextField, TextArea, Label, RadioButton, CheckBox, ListBox, ComboBox, Button, OptionPane, DialogBox, Menultem.
Answer:

Question 22.
Tanuja wants to create an interface for the following. Suggest her the most appropriate command out of TextField, RadioButton, CheckBox, ListBox, TextArea.
(i) To accept Name, Address, Phone Number from the user.
(ii) To select Gender (M/F) from the user.
(iii) To accept address from the user.
(iv) To clear the fields of the form.
Answer:
(i) The most appropriate control to accept Name, Address, Phone Number from the user is JTextField.
(ii) The most appropriate control to select Gender(M/F) is JRadioButton.
(iii) The most appropriate control to accept address from the user is JTextArea.
(iv) The most appropriate control to clear the form is JButton.

We hope the Informatics Practices Class 12 Important Questions Chapter 13 Front-End Interface help you. If you have any query regarding Informatics Practices Class 12 Important Questions Chapter 13 Front-End Interface, drop a comment below and we will get back to you at the earliest.

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NCERT Exemplar Class 6 Maths Chapter 2 Geometry are part of NCERT Exemplar Class 6 Maths. Here we have given NCERT Exemplar Class 6 Maths Solutions Chapter 2 Geometry.

NCERT Exemplar Class 6 Maths Chapter 2 Geometry

Question 1.
Number of lines passing through five points such that no three of them are collinear is
(A) 10
(B) 5
(C) 20
(D) 8
Solution:
(A) : Since, total number of points is 5 and we need two points to form a line.
∴ Total number of lines passing through the points is 5 × 2 = 10

Question 2.
The number of diagonals in a septagon is
(A) 21
(B) 42
(C) 7
(D) 14
Solution:
(D) : Since, the number of diagonals in
n(n – 3) a polygon

∵ Septagon has 7 sides, i.e., n = 7
∴ The number of diagonals in a septagon

Question 3.
Number of line segments in figure is

(A) 5
(B) 10
(C) 15
(D) 20
Solution:
(B) : The adjacent figure shows the line segments;


Thus, there are 10 line segments.

Question 4.
Measures of the two angles between hour and minute hands of a clock at 9 O’clock are
(A) 60°, 300°
(B) 270°, 90°
(c) 75°, 285°
(d) 30°, 330°
Solution:
(B)  : We know that 1 minute = 6°

∴ The number of minutes between hour and minute hands of a clock at 9 O’ clock is 15 and 45.
∴ The required angles are 15 × 6° = 90° and 45 × 6° = 270°

Question 5.
If a bicycle wheel has 48 spokes, then the angle between a pair of two consecutive spokes is




Solution:
(B) : A bicycle wheel has 48 spokes.
∴ The angle formed in circle is 360°.

Question 6.
In the given figure, ∠XYZ cannot be written as
(A) ∠Y
(B) ∠ZXY
(C) ∠ZYX
(D) ∠XYP

Solution:
(B) : In the given figure, the name of angles formed are
∠XYP, ∠XYZ, ∠PYX and ∠ZYX
Thus, ∠ZXY is not a correct option.

Question 7.
In the given figure, if point A is shifted to point B along the ray PX such that PB = 2PA, then the measure of ∠BPY is

(A) greater than 45°
(B) 45°
(C) less than 45°
(D) 90°
Solution:
(B) : Since, the increase and decrease in the length of arms of an angle does not affect the angle made by them.
∴ ∠BPY = 45°

Question 8.
The number of angles in the given figure is

(A) 3
(B) 4
(C) 5
(D) 6
Solution:
(D) : The names of angles formed in the given figure are ∠AOB, ∠AOC, ∠AOD, ∠BOC, ∠BOD and ∠COD.
There are total 6 angles formed.

Question 9.
The number of obtuse angles in figure is

(A) 2
(B) 3
(C) 4
(D) 5
Solution:
(C) : The obtuse angles formed in the
given figure are
∠AOD = 20° + 45° + 65° = 130°
∠BOD = 45° + 65° = 110°, ∠COE = 65° + 30° = 95° and ∠BOE = 45° + 65° + 30° = 140°
Thus, there are total 4 obtuse angles formed.

Question 10.
The number of triangles in the given figure is

(A) 10
(B) 12
(C) 13
(D) 14
Solution:
(C) : We have,

The names of triangles formed in the given figure are
∆ABC, ∆ABD, ∆ADC, ∆AFG, ∆AEG, ∆AFE, ∆FGD, ∆EGD, ∆FED, ∆FBD, ∆DEC, ∆AFD, ∆AED

Question 11.
If the sum of two angles is greater than 180°, then which of the following is not possible for the two angles?
(A) One obtuse angle and one acute angle
(B) One reflex angle and one acute angle
(C) Two obtuse angles
(D) Two right angles
Solution:
(D) : Since, the sum of two right angles is 180°.

Question 12.
If the sum of two angles is equal to an obtuse angle, then which of the following is not possible?
(A) One obtuse angle and one acute angle
(B) One right angle and one acute angle
(C) Two acute angles
(D) Two right angles
Solution:
(D) : Since, the sum of two right angles is 180°, which is a straight angle, not an obtuse angle.

Question 13.
A polygon has prime number of sides. Its number of sides i$ equal to the sum of the two least consecutive primes. The number of diagonals of the polygon is
(A) 4
(B) 5
(C) 7
(D) 10
Solution:
(B) : We have given, the number of sides of a polygon = Sum of the two least consecutive primes
= 2 + 3 = 5 [ ∵ 2 and 3 are the least consecutive prime numbers]
∴ The number of diagonals , where

Question 14.
In the given figure, AB = BC and AD = BD = DC. The number of isosceles triangles in the figure is

Solution:
(C) : ∵ We have, AB = BC and AD = BD = DC.
∴ ∆ ABD, ∆ BDC and ∆ ABC all are isosceles triangles.
∴ There are 3 isosceles triangles formed in the given figure.

Question 15.
In the given figure, ∠BAC = 90° and AD ⊥ BC. The number of right triangles in the figure is

Solution:
(C) : We have, ∠BAC = 90° and AD ⊥ BC
∵ ∠BDA = ∠CDA = ∠BAC = 90°
∴ There are 3 right triangles formed in the given figure.

Question 16.
In the given figure, PQ ⊥ RQ, PQ = 5 cm and QR = 5 cm. Then ∆ PQR is

(A) a right triangle but not isosceles
(B) an isosceles right triangle
(C) isosceles but not a right triangle
(D) neither isosceles nor right triangle
Solution:
(B): We have, PQ ⊥ RQ, PQ = 5 cm and QR = 5 cm, which shows that in a triangle, two sides are equal and their included angle is 90°.
∴ ∆ PQR is an isosceles right triangle.

Directions: In questions 17 to 31, fill in the blanks to make the statements true.

Question 17.
An angle greater than 180° and less than a complete angle is called ____ .
Solution:
Reflex angle

Question 18.
The number of diagonals in a hexagon is _____ .
Solution:
9 :  ∵ Number of diagonals ,
where n = 6

Question 19.
A pair of opposite sides of a trapezium are _____ .
Solution:
Parallel

Question 20.
In the given figure, points lying in the interior of the triangle PQR are ____, that in the exterior are ____ and that on the triangle itself are ____ .

Solution:
O and S; T and N; P, Q, R and M

Question 21.
In the given figure, points A, B, C, D and E are collinear such that AB = BC = CD- DE. Then

(a) AD = AB + _____
(b) AD = AC +
(c) mid point of AEis
(d) mid point of CE is
(e) AE = ___ × AB
Solution:
(a) BD : AD = AB + BC + CD = AB + BD
(b) CD : AD = AB + BC+CD = AC + CD
(c) C : ∵ AB + BC = CD + DE
⇒ AC = CE
∴ Mid point of AE is C.
(d) D : ∵ CD = DE
∴ Mid point of CE is D.
(e) 4 : ∵ AB + BC + CD + DE = AE
⇒ AB + AB + AB + AB = AE
∴ 4 AB = AE

Question 22.
In the given figure.

(a) ∠AOD is a/an ____ angle
(b) ∠COA is a/an ____ angle
(c) ∠AOE is a/an ____ angle
Solution:
(a) Right : ∠AOD = 30° + 20° + 40° = 90°
(b) Acute :∠COA = 20° + 30° = 50°
(c) Obtuse : ∠AOE = 40° + 40° + 20° + 30°
= 130°

Question 23.
The number of triangles in figure is _____. Their names are _____ .

Solution:
5, ∆ AOB, ∆ AOC, ∆COD, ∆ CAB and ∆ ACD

Question 24.
Number of angles less than 180° in given figure is ____ and their names are ____.

Solution:
12, ∠ABO, ∠BAO, ∠AOB, ∠BOD, ∠COD, ∠ODC, ∠OCD, ∠OCA, ∠CAO, ∠AOC, ∠BAC and ∠ACD.

Question 25.
The number of straight angles in given figure is ___ .

Solution:
4 : The number of straight angles in the given figure is 4.

Question 26.
The number of right angles in a straight angle is ____ and that in a complete angle is ____ .
Solution:
2, 4 : The number of right angles in a straight angle is 2 and that in a complete angle is 4.

Question 27.
The number of common points in the two angles marked in given figure is ____ .

Solution:
Two : The two angles marked; ∠PAQ and ∠PDQ
∴ The number of common points are 2 and these are P and Q.

Question 28.
The number of common points in the two angles marked in given figure is ____ .

Solution:
One : The two angles marked; ∠CAB and ∠DAE.
∴ The number of common point is 1 and that is A.

Question 29.
The number of common points in the two angles marked in given figure

Solution:
Three : There are 3 common points in the two angles marked in the given figure and these are P, Q and R.

Question 30.
The number of common points in the two angles marked in the given figure is ______

Four : The number of common points in the two angles marked in the given figure is 4 and these are E, D, G and F

Question 31.
The common part between the two angles BAC and DAB in given figure is ____.

Solution:
Ray

Directions: State whether the statements given in questions 32 to 41 are true (T) or false (F).
Question 32.
A horizontal line and a vertical line always intersect at right angles.
Solution:
True

Question 33.
If the arms of an angle on the paper are increased, the angle increases.
Solution:
False
If the arms of an angle on the paper are increasing or decreasing, it doesn’t affect the angle made by them.

Question 34.
If the arms of an angle on the paper are decreased, the angle decreases.
Solution:
False
If the arms of an angle on the paper are increasing or decreasing, it doesn’t affect the angle made by them.

Question 35.
If line PQ || line m, then line segment PQ || m
Solution:
True

Question 36.
Two parallel lines meet each other at some point.
Solution:
False
Two lines in a plane which do not meet even when produced indefinitely in either direction, are known as parallel lines.

Question 37.
Measures of ∠ABC and ∠CBA in given figure are the same.

Solution:
True
∵ ∠ABC is same as ∠CBA.

Question 38.
Two line segments may intersect at two points.
Solution:
False
The intersecting point of any two line segments is only one.

Question 39.
Many lines can pass through two given points.
Solution:
False
∵ There is only one line which passes through two given points.

Question 40.
Only one line can pass through a given point.
Solution:
False
∵ There are infinite number of lines which passes through a given point.

Question 41.
Two angles can have exactly five points in common.
Solution:
False
∵ It can have any number of points.

Question 42.
Name all the line segments in given figure.

Solution:
The line segments are AB, BC, CD, DE, AC, AD, AE, BD, BE and CE

Question 43.
Name the line segments shown m given figure.

Solution:
The line segments are
AB, BC, CD, DE and EA

Question 44.
State the mid points of all the sides of given figure.

Solution:
X is a mid-point of AC,
Y is a mid-point of BC and
Z is a mid-point of AB.

Question 45.
Name the vertices and the line segments in given figure.

Solution:
The vertices are : A, B, C, D and E.
The line segments are : AB, BC, CD, DE, EA, AC and AD.

Question 46.
Write down fifteen angles (less than 180°) involved in given figure.

Solution:
The names of fifteen angles (less than 180°) involved in figure are :
∠AEC, ∠ADB, ∠EAD, ∠EFD, ∠EFB, ∠DFC, ∠FBC, ∠FCB, ∠BFC, ∠ABC, ∠ACB, ∠DCF, ∠FDC, ∠EBF and ∠BEF.

Question 47.
Name the following angles of given figure, using three letters:

(a) ∠1
(b) ∠2
(c) ∠3
(d) ∠1 + ∠2
(e) ∠2 + ∠3
(f) ∠1 + ∠2 + ∠3
(g) ∠CBA – ∠1
Solution:
(a) ∠1 = ∠CBD
(b) ∠2 = ∠DBE
(c) ∠3 = ∠EBA
(d) ∠1 + ∠2 = ∠CBD + ∠DBE = ∠CBE
(e) ∠2 + ∠3 = ∠DBE + ∠EBA = ∠DBA
(f) ∠l + ∠2 + ∠3 = ∠CBD + ∠DBE + ∠EBA
= ∠CBA
(g) ∠CBA – ∠1 = ∠CBA – ∠CBD = ∠DBA

Question 48.
Name the points and then the line segments in each of the following figures:

Solution:
(i) Name of the points ➝ A, B and C. Name of the line segments ➝ AB, BC and CA.
(ii) Name of the points ➝ A, B, C and D. Name of the line segments ➝ AB, BC, CD and DA.
(iii) Name of the points ➝ A, B, C, D and E. Name of the line segments ➝ AB, BC, CD, DE and EA.
(iv) Name of the points ➝ A, B, C, D, E and F.
Name of the line segments ➝ AB, CD and EF.

Question 49.
Which points in given figures, appear to be mid-points of the line segments? When you locate a mid-point, name the two equal line segments formed by it.

Solution:
(i) The given figure shows there is no mid-point.
(ii) The given figure shows that O is the mid-point of ZB and the name of the two equal line segments are AC and OB.
(iii) The given figure shows that D is the mid-point of BC and the name of the two equal line segments are BD and DC.

Question 50.
Is it possible for the same
(a) line segment to have two different lengths?
(b) angle to have two different measures?
Solution:
(a) No, it is not possible for the same line segment to have two different lengths.
(b) No, it is not possible for the same angle to have two different measures.

Question 51.
Will the measure of ∠ABC and of ∠CBD make measure of ∠ABD in given figure?

Solution:
Yes, ∵ ∠ABD = ∠ABC + ∠CBD
⇒ ∠ABD is the sum of ∠ABC and ∠CBD

Question 52.
Will the lengths of line segment AB and line segment BC make the length of line segment AC in given figure?

Solution:
Yes, ∵ the length of line segment AC is the sum of the lengths of line segment AB and BC.

Question 53.
Draw two acute angles and one obtuse angle without using a protractor. Estimate the measures of the angles. Measure them with the help of a protractor and see how much accurate is your estimate.
Solution:
Do it yourself.

Question 54.
Look at a given figure. Mark a point

(a) A which is in the interior of both ∠1  and ∠2.
(b) B which is in the interior of only ∠1.
(c) Point C in the interior of ∠1.
Now, state whether points B and C lie in the interior of ∠2 also.
Solution:
Yes, the given figure shows that the points B and C lie in the interior of ∠2 also.

Question 55.
Find out the incorrect statement, if any, in the following : An angle is formed when we have
(a) two rays with a common end-point
(b) two line segments with a common end-point
(c) a ray and a line segment with a common end-point
Solution:
All the three statements (a), (b) and (c) are incorrect.
∵ The common initial point of two rays forms an angle.

Question 56.
In which of the following figures,
(a) perpendicular bisector is shown?
(b) bisector is shown?
(c) only bisector is shown?
(d) only perpendicular is shown?

Solution:
(a) Figure (ii) shows the perpendicular bisector
(b) Figure (ii) and (iii) shows the bisector.
(c) Figure (iii) shows only the bisector.
(d) Figure (i) shows only the perpendicular.

Question 57.
What is common in the following figures (i) and (ii)?

Is figure (i) that of triangle ? if not, why?
Solution:
Both the figures (i) and (ii) have 3 line segments.
No, Fig. (i) is not a triangle since the three line segments does not form a closed figure.

Question 58.
If two rays intersect, will their point of intersection be the vertex of an angle of which the rays are the two sides?
Solution:
Yes

Question 59.
In given figure,

(a) name any four angles that appear to be acute angles.
(b) name any two angles that appear to be obtuse angles.
Solution:
(a) Acute angles : ∠ADE, ∠AEB, ∠ABE and ∠ECD.
(b) Obtuse angles : ∠BCD and ∠BAD.

Question 60.
In given figure,

(a) is AC + CB = AB ?
(b) is AB + AC= CB ?
(c) is AB + BC = CA ?
Solution:
(a) Yes, AC + CB = AB
(b) No, AB – AC = CB
(c) No, AB – BC = CA

Question 61.
In given figure

(a) What is AB + BC?
(b) What is AC – EC?
(c) What is BD – BE?
(d) What is BD – DE?
Solution:
(a) AE + EC = AC
(b) AC – EC = AE
(c) BD – BE = ED
(d) BD – DE = BE

Question 62.
Using the information given, name the right angles in each part of given figures.



Solution:
(a) ∵ BA ⊥ BD,
∴ The right angle is ∠ABD
(b) ∵ RT ⊥ ST, ∴ The right angle is ∠RTS
(c) ∵ AC ⊥ BD,
∴ The right angles are ∠ACD and ∠ACB
(d) ∵ RS ⊥ RW,
∴ The right angle is ∠SRW
(e) ∵ AC ⊥ BD,
∴ The right angles are ∠AED, ∠AEB, ∠BEC and ∠CED
(f) ∵ AE ⊥ CE,
∴ The right angle is ∠AEC
(g) ∵ AC ⊥ CD,
∴ The right angle is ∠ACD
(h) ∵ OP ⊥ AB,
∴ The right angles are ∠AKO, ∠AKP, ∠BKO and ∠BKP.

Question 63.
What conclusion can be drawn from each part of given figures, if
(a) DB is the bisector of ∠ADC?

Solution:
(a) ∵ DB is the bisector of ∠ADC.
∴ ∠ADB = ∠CDB
(b) ∵ BD bisects ZABC.
∴ ∠ABD = ∠CBD
(c) ∵ DC is the bisector of ∠ADB,
CA ⊥ DA and CB ⊥ DB
∠ADC = ∠BDC, ∠CAD = ∠CBD = 90°

Question 64.
An angle is said to be trisected, if it is divided into three equal parts. If in a given figure, ∠BAC = ∠CAD = ∠DAE, how many trisectors are there for ∠BAE ?

Solution:
We have given, ∠BAC = ∠CAD = ∠DAE
∴ There are two trisectors namely, AC and AD.

Question 65.
How many points are marked in given figure?

Solution:
Two points A and B are marked.

Question 66.
How many line segments are there in given figure?

Solution:
Only one line segment, AB is there.

Question 67.
In given figure, how many points are marked? Name them.

Solution:
Three points A, B and C are marked.

Question 68.
How many line segments are there in given figure? Name them.

Solution:
Three line segments, namely AB, BC and AC are there.

Question 69.
In given figure, how many points are marked? Name them.

Solution:
Four points A, B, C and D are marked.

Question 70.
In given figure how many line segments are there? Name them.

Solution:
Six line segments, namely AB, AC, AD, BC, BD and CD.

Question 71.
In given figure, how many points are marked? Name them.

Solution:
Five points are marked, namely A, B, D, E and C.

Question 72.
In given figure how many line segments are there? Name them.

Solution:
Ten line segments, namely AB, AD, AE, AC, BD, BE, BC, DE, DC and EC.

Question 73.
In given figure, O is the centre of the circle.

(a) Name all chords of the circle.
(b) Name all radii of the circle.
(c) Name a chord, which is not the diameter of the circle.
(d) Shade sectors OAC and OPB.
(e) Shade the smaller segment of the circle formed by CP.
Solution:
(a) Name of chords : PC and BA.
(b) Name of radii : PO, OC, OB and OA.
(c) PC is a chord which is not the diameter of the circle.

Question 74.
Can we have two acute angles whose sum is
(a) an acute angle? Why or why not?
(b) a right angle? Why or why not?
(c) an obtuse angle? Why or why not?
(d) a straight angle? Why or why not?
(e) a reflex angle? Why or why not?
Solution:
(a) Yes, ∵ the sum of two acute angles can be the acute angle.
E.g„ 30° and 40° are two acute angles and their sum = 30° + 40° = 70°, which is also an acute angle.
(b) Yes, ∵ the sum of two acute angles can be a right angle.
E.g., 30° and 60° are two acute angles and their sum = 30° + 60° = 90°, which is a right angle.
(c) Yes, ∵ the sum of two acute angles can be an obtuse angle.
E.g., 45° and 60° are two acute angles and their sum = 45° + 60° = 105°, which is an obtuse angle.
(d) No, ∵ the sum of two acute angles is always less than 180°.
(e) No, ∵ the sum of two acute angles is always less than 180°.

Question 75.
Can we have two obtuse angles whose sum is
(a) a reflex angle? Why or why not?
(b) a complete angle? Why or why not?
Solution:
(a) Yes, ∵ the sum of two obtuse angles is always greater than 180°.
E.g., 135° and 100° are two obtuse angles and their sum = 135° + 100° = 235°, which is greater than 180°.
(b) No, ∵ the sum of two obtuse angles is greater than 180° but less than 360°. In the above example, we can see that the sum of 135° and 100° i.e., 235° is greater than 180° but less than 360°.

Question 76.
Write the name of
(a) vertices
(b) edges, and
(c) faces of the prism shown in given figure.

Solution:
(a) Vertices : A, B, C, D, E and F.
(b) Edges : AB, BC, AC, DF, FC, BD, EF, ED and AE.
(c) Faces : EACF, EDBA, ABC, DEF and DBCF.

Question 77.
How many edges, faces and vertices are there in a sphere?
Solution:
In a sphere, edges – 0, faces – 0 and vertices – 0.

Question 78.
Draw all the diagonals of a pentagon ABCDE and name them.
Solution:
The diagonals of a pentagon ABCDE are AC, AD, BE, BD and EC

We hope the NCERT Exemplar Class 6 Maths Chapter 2 Geometry will help you. If you have any query regarding NCERT Exemplar Class 6 Maths Chapter 2 Geometry, drop a comment below and we will get back to you at the earliest.

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CBSE Class 8 Science Notes Chapter 14 Chemical Effects of Electric Current Pdf free download is part of Class 8 Science Notes for Quick Revision. Here we have given NCERT Class 8 Science Notes Chapter 14 Chemical Effects of Electric Current.

CBSE Class 8 Science Notes Chapter 14 Chemical Effects of Electric Current

Some liquids are good conductors of electricity and some are poor conductors.

Most liquids that conduct electricity are the solution of acids, bases and salts.

Water: A Conductor or Insulator: The water that we get from sources such as tap, hand pumps, wells, ponds is not pure but a solution. The small number of mineral salts are naturally present in it. This water is thus a conductor of electricity. On the other hand, distilled water is free of salts, and thus an insulator.

Due to the heating effect of current, the filament of the bulb of the tester gets heated to a high temperature and it glows. Light emitting diodes (LED) glow even when a weak electric current flows through it.

Chemical Effects of Electric Current: The passage of an electric current through a conducting solution causes the chemical reaction. The resulting effects are called chemical effects of current.

Electroplating is an example of a chemical effect of current.

Applications of Electroplating: Electroplating is a very useful process. It is widely used for coating many metal objects and parts with a thin layer of a different metal.

Electrode: It is the metallic rod/conductor through which electricity enters or leaves an electrolyte.

Electroplating: The process of depositing a layer of any desired metal on another metallic object, by means of electricity, is called electroplating.

Good Conductors: The materials that allow the electric current to pass through them, are conductors of electricity. For example: Metals such as copper, aluminium.

LED: These are Light Emitting Diodes that contain two wires called leads. One lead slightly longer is always connected to the positive terminal of battery while the other lead is connected to the negative terminal of the battery.

Poor Conductors or Insulators: The materials, which do not allow an electric current to pass through them easily, are insulators. For example Rubber, plastic and wood.

We hope the given CBSE Class 8 Science Notes Chapter 14 Chemical Effects of Electric Current Pdf free download will help you. If you have any query regarding NCERT Class 8 Science Notes Chapter 14 Chemical Effects of Electric Current, drop a comment below and we will get back to you at the earliest.

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