CBSE Class 7 Science Heat Transfer in Nature (Class 7 NCERT New) Quiz 9

1. Which natural process gradually releases water from an ice stupa during warmer months?

A Condensation of water vapor B Sublimation of solid ice C Melting and phase change D Freezing of liquid streams

2. A village builds ice stupas each winter to store meltwater for irrigation. If spring temperatures rise faster than usual, which plan best ensures a steady water supply into summer?

A Break the ice to increase surface area B Place stupas on sunny slopes for quick melt C Color the ice dark to absorb more heat D Construct taller stupas to melt more slowly

3. Conduction is the transfer of heat through...

A radiation B absence of particles C movement of liquid D direct contact between particles

4. What is an example of conduction?

A When a cat sits on a warm blanket B When a person blows on hot soup to cool it down C When a plant absorbs sunlight for photosynthesis D When a metal spoon is placed in a hot cup of coffee

5. How does conduction occur in solids?

A Through the transfer of sound waves B By the movement of electrons within the material C Through the transfer of light energy D Through the transfer of heat energy from one particle to another within the material.

6. What is convection and how does it work?

A Convection is the transfer of heat through solid materials like metal or wood. B Convection is the transfer of heat through the movement of fluids (liquids or gases). C Convection works by the movement of solids instead of fluids. D Convection is the transfer of heat through electromagnetic waves.

7. Give an example of convection in everyday life.

A Baking cookies in the oven B Lighting a candle C Boiling water in a pot D Freezing water in the freezer

8. How does convection occur in liquids and gases?

A Warmer particles rise and cooler particles sink B Particles move from left to right C Particles move randomly in all directions D Particles move in a circular motion

9. What is radiation and how does it differ from conduction and convection?

A Radiation is the transfer of heat through solid materials. B Radiation is the transfer of heat through chemical reactions. C Radiation is the transfer of heat through sound waves. D Radiation is the transfer of heat through electromagnetic waves.

10. What are some examples of radiation in nature?

A Infrared radiation, ultraviolet radiation, radio waves B Sunlight, heat from a fire, warmth from a hot sidewalk C Microwaves, X-rays, Gamma rays D Visible light, sound waves, magnetic fields