๐ Class 7 Science Curiosity – Chapter 7 Solutions
๐ฅ Heat Transfer in Nature | Amresh Academy
๐ ๐น Let Us Enhance Our Learning
1. Choose the correct option in each case.
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.
3. State with reason(s) whether the following statements are True [T] or False [F].
4. Some ice cubes placed in a dish melt into water after sometime. Where do the ice cubes get heat for this transformation?
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.
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.
7. Why are hollow bricks used to construct the outer walls of houses in hot regions?
8. Explain how large water bodies prevent extreme temperature in areas around them.
9. Explain how water seeps through the surface of the Earth and gets stored as groundwater.
10. The water cycle helps in the redistribution and replenishment of water on the Earth. Justify the statement.
✍️ ๐น Very Short Answer Type Questions
What is conduction?
๐ Heat transfer without particle movement
Which materials are poor conductors of heat?
๐ Wood, plastic, air, wool
Why is a metal pan used for cooking?
๐ Good conductor ๐ฅ
Name the three modes of heat transfer.
๐ Conduction, convection, radiation
Which process allows heat transfer from the Sun to Earth?
๐ Radiation ☀️
๐ง ๐น Short Answer Type Questions
Why do pins attached to a metal strip fall one after the other during heating?
๐ Heat travels step by step → wax melts
Why do we wear woollen clothes in winter?
๐ Air trapped → prevents heat loss
What causes land and sea breeze?
๐ Temperature difference ๐
How does a bukhari keep a room warm?
๐ Conduction + convection + radiation
Why is it comfortable to wear white clothes in summer?
๐ Reflect heat ☀️
๐ ๐น Descriptive Answer Type Questions
Explain the process of convection in liquids using an activity.
How does the use of hollow bricks help in temperature control in houses?
๐ Air insulation ๐
What is infiltration and how does it affect groundwater levels?
๐ Water seeps → stored underground
How does heat transfer through radiation differ from conduction and convection?
๐ Radiation → no medium needed
Explain the water cycle using heat transfer processes.
๐ Evaporation → condensation → rain ๐ง️
๐ ๐น Exploring Questions
Why does smoke from incense or firewood rise upward?
๐ Hot air rises ๐ฅ⬆️
Why is water served in clay or porcelain cups instead of metal ones during summers?
๐ Poor conductors → keep cool ๐ง
Why do we feel warm even when we sit at a distance from a fire?
๐ Radiation ๐ฅ
What are aquifers and why are they important for survival?
๐ Underground water storage ๐ง
How do ice stupas in Ladakh help in water conservation?
๐ Store water as ice ❄️ → melt later
