Fire: Friend and Foe class 7 NCERT Solutions
Fire: Friend and Foe class 7 NCERT Solutions: Fire: Friend and Foe is the chapter 8 from class 7 NCERT, English textbook Honeycomb. Here you will get Fire: Friend and Foe class 7 NCERT Solutions.
Fire: Friend and Foe class 7 Summary in English
In earlier times, Early man must have found fire to be dangerous and frightening. They must have experienced lighting only. Fire must have been a mystery for an early man knowing its origin.
Today it is known that fire is a result of chemical reaction. When oxygen present in air combines with carbon and hydrogen present in a fuel, energy is released in form of heat and light and this is what fire is.
Every fuel burns at a particular temperature which is also called ‘flash point or kindling temperature. Where oxygen combines with carbon and hydrogen in a fuel. During this process, energy is released in the form of heat and light. Fuel, oxygen and all are the three things required to make fire.
The flashpoint or kindling temperature of the fuel varies with every fuel. Fire is a good servant as it cooks the food and gives warmth in winters. It is also a bad master because it damages and turns everything into ash if not used wisely.
Fire can be put out by taking away the fuel, by preventing oxygen supply to the fire and by removing the heat. Fire can put off if there is no fuel to burn. Usage of damp blanket or sack, carbon dioxide does not allow oxygen to reach the burning material.
If the temperature can be brought down below the flashpoint, the fuel stops burning. Fire can be put out carbon dioxide extinguisher not by water like on out fire and on electrical appliances. The water can flow quickly, carrying the burning oil thus spreading the fire. One may receive an electric shock if the water is spread on an electronic fire.
In older times, people formed a human chain to get water from ponds. But nowadays, millions of rupees are spent on technological advancements to control fire. Fire brigades are formed to take the challenge and put down fire easily.
In order to avoid loss and control destruction we should be aware of preventive measures like every new building has to follow and observe fire prevention norms and install fire extinguishers at home or in public places. Fire is a friend who can turn into a foe if it is left unattended. So careful use of fire is sought after.
Fire: Friend and Foe class 7 Summary in Hindi
पहले के समय में, प्रारंभिक मनुष्य ने आग को खतरनाक और भयावह माना होगा। उन्हें केवल प्रकाश का अनुभव होना चाहिए। आग की उत्पत्ति जानने वाले एक प्रारंभिक व्यक्ति के लिए एक रहस्य रहा होगा।
आज यह ज्ञात है कि आग रासायनिक प्रतिक्रिया का परिणाम है। जब हवा में मौजूद ऑक्सीजन ईंधन में मौजूद कार्बन और हाइड्रोजन के साथ मिलती है, तो ऊर्जा गर्मी और प्रकाश के रूप में निकलती है और यही आग है।
अग्नि को ईंधन बनाने के लिए ऊष्मा और ऑक्सीजन की आवश्यकता होती है। लकड़ी, कोयला, गैस ईंधन हैं, हवा में ऑक्सीजन उपलब्ध है। लेकिन आग पैदा करने के लिए गर्मी जरूरी है। कागज का एक टुकड़ा तब तक आग नहीं पकड़ता जब तक कि उसे आपूर्ति नहीं की जाती। प्रत्येक ईंधन एक विशेष तापमान पर जलता है जिसे 'फ्लैश पॉइंट या किंडलिंग तापमान' भी कहा जाता है।
जहां ईंधन में ऑक्सीजन कार्बन और हाइड्रोजन के साथ मिलती है। इस प्रक्रिया के दौरान, ऊर्जा गर्मी और प्रकाश के रूप में निकलती है। आग बनाने के लिए ईंधन, ऑक्सीजन और तीनों चीजें आवश्यक हैं।
ईंधन का फ्लैशपॉइंट या जलाने का तापमान हर ईंधन के साथ बदलता रहता है। आग एक अच्छी सेवक है क्योंकि यह खाना बनाती है और सर्दियों में गर्मी देती है। यह एक बुरा स्वामी भी है क्योंकि यह बुद्धिमानी से उपयोग न करने पर हर चीज को नुकसान पहुंचाता है और राख में बदल देता है।
आग को ऑक्सीजन की आपूर्ति को रोककर और गर्मी को दूर करके, ईंधन को हटाकर, आग को बुझाया जा सकता है। अगर जलने के लिए ईंधन नहीं है तो आग बुझाई जा सकती है। नम कंबल या बोरी का उपयोग, कार्बन डाइऑक्साइड ऑक्सीजन को जलती हुई सामग्री तक नहीं पहुंचने देता है।
यदि तापमान को फ्लैशपॉइंट से नीचे लाया जा सकता है, तो ईंधन जलना बंद कर देता है। आग को जल से नहीं, जैसे आग पर और बिजली के उपकरणों से नहीं, कार्बन डाइऑक्साइड बुझाने वाले यंत्र से बुझाया जा सकता है। जल तेजी से बह सकता है, जलते हुए तेल को ले जाकर आग फैला सकता है। अगर इलेक्ट्रॉनिक आग पर पानी फैलाया जाता है तो किसी को बिजली का झटका लग सकता है।
पुराने समय में लोग तालाबों से पानी लेने के लिए मानव श्रृंखला बनाते थे। लेकिन आजकल आग पर काबू पाने के लिए तकनीकी विकास पर लाखों रुपये खर्च किए जाते हैं। चुनौती लेने और आसानी से आग पर काबू पाने के लिए फायर ब्रिगेड का गठन किया जाता है।
नुकसान से बचने और विनाश को नियंत्रित करने के लिए हमें निवारक उपायों के बारे में पता होना चाहिए जैसे कि हर नए भवन में आग से बचाव के मानदंडों का पालन करना और उनका पालन करना और घर या सार्वजनिक स्थानों पर अग्निशामक यंत्र स्थापित करना है। आग एक मित्र है जो बिना ध्यान दिए रहने पर दुश्मन में बदल सकती है। इसलिए आग का सावधानीपूर्वक उपयोग करने की मांग की जाती है।
NCERT Solutions of Fire: Friend and Foe class 7 English
Comprehension Check
1. Mark the correct answer in each of the following.
(i) Early man was frightened of
(a) lightning and volcanoes.
(b) the damage caused by them.
(c) fire.
Ans: fire
(ii) (a) Fire is energy.
(b) Fire is heat and light.
(c) Fire is the result of a chemical reaction.
Ans: Fire is the result of chemical reaction
2. From the boxes given below choose the one with the correct order of the following sentences.
(i) That is fire.
(ii) A chemical reaction takes place.
(iii) Energy in the form of heat and light is released.
(iv) Oxygen combines with carbon and hydrogen.
(i) (ii) (iii) (iv) (ii) (iii) (i) (iv)
(iv) (iii) (ii) (i) (iv) (ii) (iii) (i)
Ans: (iv) (ii) (iii) (i)
Working with the Text
Answer the following questions.
1. What do you understand by the ‘flash point’ of a fuel ?
Ans: The 'flash point' of a fuel the temperature at which a fuel begins to burn.
2. (i) What are some common uses of fire ?
(ii) In what sense is it a “bad master” ?
Ans: (i) Some of the common uses of fire are cooking, producing electricity, to keep our home and us warm during winter.
(ii) Fire is a "bad master" in sense if it goes out of control, it can cause damage to our life, house and property.
3. Match items in Column A with those in Column B.
Ans: A B
4. What are the three main ways in which a fire can be controlled or put out ?
Ans: Fire can be controlled or put out by taking away the fuel, stopping the supply of oxygen or by lowering down the flash point around the fuel.
5. Match the items in Box A with those in Box B
Ans:
(i) To burn paper or a piece of wood — we heat it before it catches fire.
(ii) Small fires can be put out — with a damp blanket.
(iii) When water is spread on fire — it absorbs heat from the burning material and lowers the temperature.
(iv) A carbon dioxidc extinguisher is the best thing — to put out an electrical fire.
(v) Space left between buildings — reduces the risk of fire.
6. Why does a burning candle go out when you blow on it ?
Ans: A burning candle goes out when we blow on it because blowing removes the hot air around the flame, bringing down its temperature below the flash point.
7. Spraying water is not a good way of putting out an oil fire or an electrical fire. Why not ?
Ans: Spraying water is not a good way of putting out an oil fire or an electrical fire because if water is sprayed onto an oil fire, then the oil will float to the top of the water and continue to burn. This can be very dangerous because water can flow quickly, carrying the burning oil with it and spreading the fire. In case of an electrical fire, the person spraying water might receive an electric shock and be killed.
8. What are some of the things you should do to prevent a fire at home and in the school ?
Ans: Some of the things we should do to prevent a fire at home and in the school are
(i) We should keep away highly inflammable substances and handle them with care.
(ii) Fire extinguisher should be installed and old wiring must be replaced.
(iii) We should not store petrol, diesel, kerosene at home or schools. etc.
NCERT Solutions for Fire: Friend and Foe class 7 English
Working with Language
1. Read the following sentences.
To burn paper or a piece of wood, we heat it before it catches fire. We generally do it with a lighted match. Every fuel has a particular temperature at which it burns.
The verbs in italics are in the simple present tense. When we use it, we are not thinking only about the present. We use it to say that something happens all the time or repeatedly, or that something is true in general.
______________________ ______________________ ______________________
______________________ ______________________ ______________________
______________________ ______________________ ______________________
Find ten examples of verbs in the simple present tense in the text ‘Fire: Friend and Foe’ and write them down here. Do not include any passive verbs.
Ans:
(i) Fire is the result of a chemical reaction.
(ii) This is what we call fire.
(iii)To burn a piece of paper or wood, we heat it before it catches fire.
(iv) Oxygen comes from the air.
(v) It is sometimes said that fire is a good servant, but a bad master.
(vi) The third way to putting out a fire is to remove heat.
(vii) We spend millions of rupees each year in fighting fire.
(viii) It absorbs heat from burning fuel.
(ix) It only means that fire is very useful.
(x) Fire is still worshipped in many parts of the world.
Fire: Friend and Foe class 7 Questions Answers
2. Fill in the blanks in the sentences below with words from the box. You may use a word more than once.
carbon cause fire smother
(i) Gandhiji’s life was devoted to the ______________________ of justice and fair play.
(ii) Have you insured your house against ______________________ ?
(iii) Diamond is nothing but ______________________ in its pure form.
(iv) If you put too much coal on the fire at once you will ______________________ it.
(v) Smoking is said to be the main ______________________ of heart disease.
(vi) When asked by an ambitious writer whether he should put some ______________________ into his stories, Somerset Maugham murmured, “No, the other way round”.
(vii) She is a ______________________ copy of her mother.
(viii) It is often difficult to ______________________ a yawn when you listen to a long speech on the value of time.
Ans:
(i) Gandhiji’s life was devoted to the cause of justice and fair play.
(ii) Have you insured your house against fire ?
(iii) Diamond is nothing but carbon in its pure form.
(iv) If you put too much coal on the fire at once you will smother it.
(v) Smoking is said to be the main cause of heart disease.
(vi) When asked by an ambitious writer whether he should put some fire into his stories, Somerset Maugham murmured, “No, the other way round”.
(vii) She is a carbon copy of her mother.
(viii) It is often difficult to smother a yawn when you listen to a long speech on the value of time.
3. One word is italicised in each sentence. Find its opposite in the box and fill in the blanks.
spending shut destroy subtract increase
(i) You were required to keep all the doors open, not ______________________
(ii) PUPIL: What mark did I get in yesterday’s Maths test ?
TEACHER: You got what you get when you add five and
five and ______________________ ten from the total.
(iii) Run four kilometres a day to preserve your health.
Run a lot more to ______________________ it.
(iv) If a doctor advises a lean and lanky patient to
reduce his weight further, be sure he is doing it to
______________________ his income.
(v) The world is too much with us; late and ______________________ soon, Getting and we lay waste our powers.
– WORDSWORTH
Ans:
i) You were required to keep all the doors open, not shut.
(ii) PUPIL: What mark did I get in yesterday’s Maths test ?
TEACHER: You got what you get when you add five and
five and subtract ten from the total.
(iii) Run four kilometres a day to preserve your health.
Run a lot more to destroy it.
(iv) If a doctor advises a lean and lanky patient to reduce his weight further, be sure he is doing it to increase his income.
(v) The world is too much with us; late and spending soon, Getting and we lay waste our powers.
– WORDSWORTH
4. Use the words given in the box to fill in the blanks in the sentences below.
across along past through
(i) The cat chased the mouse ______________________ the lawn.
(ii) We were not allowed to cross the frontier. So we drove ______________________ it as far as we could and came back happy.
(iii) The horse went ______________________ the winning post and had to be stopped with difficulty.
(iv) It is not difficult to see ______________________ your plan. Anyone can see your motive.
(v) Go ______________________ the yellow line, then turn left. You Will reach the post office in five minutes.
Ans:
(i) The cat chased the mouse across the lawn.
(ii) We were not allowed to cross the frontier. So we drove along it as far as we could and came back happy.
(iii) The horse went past the winning post and had to be stopped with difficulty.
(iv) It is not difficult to see through your plan. Anyone can see your motive.
(v) Go along the yellow line, then turn left. You will reach the post office in five minutes.
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