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Class 7 Science Chapter 7 Heat Transfer in Nature Solutions | Curiosity NCERT Answers 2026-27 | Amresh Academy

 


 

🌟 Class 7 Science Curiosity – Chapter 7 Solutions

🔥 Heat Transfer in Nature | Amresh Academy


📝 🔹 Let Us Enhance Our Learning


1. Choose the correct option in each case.

(i) Your father bought a saucepan made of two different materials, A and B, as shown in Fig. 7.14. The materials A and B have the following properties-
(a) Both A and B are good conductors of heat
(b) Both A and B are poor conductors of heat
(c) A is a good conductor and B is a poor conductor of heat
(d) A is a poor conductor and B is a good conductor of heat

👉 Answer:
✔️ (c) A is a good conductor and B is a poor conductor of heat
🔥 Pan conductor
🖐️ Handle insulator


(ii) Pins are stuck to a metal strip with wax and a burning candle is kept below the rod, as shown in Fig. 7.15. Which of the following will happen?
(a) All the pins will fall almost at the same time
(b) Pins I and II will fall earlier than pins III and IV
(c) Pins I and II will fall later than pins III and IV
(d) Pins II and III will fall almost at the same time

👉 Answer:
✔️ (b) Pins I and II will fall earlier than pins III and IV
🔥 Heat travels step by step wax melts sequentially


(iii) A smoke detector is a device that detects smoke and sounds an alarm. Suppose you are fitting a smoke detector in your room. The most suitable place for this device will be:
(a) Near the floor
(b) In the middle of a wall
(c) On the ceiling
(d) Anywhere in the room

👉 Answer:
✔️ (c) On the ceiling
💨 Smoke rises due to convection


2. A shopkeeper serves you cold lassi in a tumbler. By chance, the tumbler had a small leak. You were given another tumbler by the shopkeeper to put the leaky tumbler in it. Will this arrangement help to keep the lassi cold for a longer time? Explain.

👉 Answer:
✔️ Yes
🧊 Air between tumblers = insulator
➡️ Slows heat transfer lassi stays cold longer


3. State with reason(s) whether the following statements are True [T] or False [F].

(i) Heat transfer takes place in solids through convection. [ ]
(ii) Heat transfer through convection takes place by the actual movement of particles. [ ]
(iii) Areas with clay materials allow more seepage of water than those with sandy materials. [ ]
(iv) The movement of cooler air from land to sea is called land breeze. [ ]

👉 Answer:
(i) False conduction in solids
(ii) True
(iii) False sand allows more seepage
(iv) True


4. Some ice cubes placed in a dish melt into water after sometime. Where do the ice cubes get heat for this transformation?

👉 Answer:
🌡️ From surroundings (air + dish)


5. A burning incense stick is fixed, pointing downwards. In which direction would the smoke from the incense stick move? Show the movement of smoke with a diagram.

👉 Answer:
⬆️ Smoke moves upward
💨 Hot air rises (convection)


6. Two test tubes with water are heated by a candle flame as shown in Fig. 7.16. Which thermometers (Fig. 7.16a or Fig. 7.16b) will record a higher temperature? Explain.

👉 Answer:
✔️ Fig. 7.16b
🔥 Heating from bottom convection currents faster heating


7. Why are hollow bricks used to construct the outer walls of houses in hot regions?

👉 Answer:
🏠 Air trapped poor conductor
➡️ Keeps house cool


8. Explain how large water bodies prevent extreme temperature in areas around them.

👉 Answer:
🌊 Water heats & cools slowly
☀️ Day absorbs heat
🌙 Night releases heat
➡️ Temperature remains moderate


9. Explain how water seeps through the surface of the Earth and gets stored as groundwater.

👉 Answer:
💧 Water seeps through soil (infiltration)
⬇️ Stored in aquifers


10. The water cycle helps in the redistribution and replenishment of water on the Earth. Justify the statement.

👉 Answer:
🌧️ Evaporation Condensation Precipitation
➡️ Water circulates & refills sources


✍️ 🔹 Very Short Answer Type Questions


What is conduction?

👉 Heat transfer without particle movement


Which materials are poor conductors of heat?

👉 Wood, plastic, air, wool


Why is a metal pan used for cooking?

👉 Good conductor 🔥


Name the three modes of heat transfer.

👉 Conduction, convection, radiation


Which process allows heat transfer from the Sun to Earth?

👉 Radiation ☀️


🧠 🔹 Short Answer Type Questions


Why do pins attached to a metal strip fall one after the other during heating?

👉 Heat travels step by step wax melts


Why do we wear woollen clothes in winter?

👉 Air trapped prevents heat loss


What causes land and sea breeze?

👉 Temperature difference 🌍


How does a bukhari keep a room warm?

👉 Conduction + convection + radiation


Why is it comfortable to wear white clothes in summer?

👉 Reflect heat ☀️


📖 🔹 Descriptive Answer Type Questions


Explain the process of convection in liquids using an activity.

👉 Heated water rises 🔥⬆️
Cool water sinks ❄️⬇️
➡️ Circular motion


How does the use of hollow bricks help in temperature control in houses?

👉 Air insulation 🏠


What is infiltration and how does it affect groundwater levels?

👉 Water seeps stored underground


How does heat transfer through radiation differ from conduction and convection?

👉 Radiation no medium needed


Explain the water cycle using heat transfer processes.

👉 Evaporation condensation rain 🌧️


🚀 🔹 Exploring Questions


Why does smoke from incense or firewood rise upward?

👉 Hot air rises 🔥⬆️


Why is water served in clay or porcelain cups instead of metal ones during summers?

👉 Poor conductors keep cool 🧊


Why do we feel warm even when we sit at a distance from a fire?

👉 Radiation 🔥


What are aquifers and why are they important for survival?

👉 Underground water storage 💧


How do ice stupas in Ladakh help in water conservation?

👉 Store water as ice ❄️ melt later


 

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