CBSE Class 7 Science Heat Transfer in Nature (Class 7 NCERT New) Quiz 10

1. How does insulation help in reducing heat transfer?

A Insulation conducts heat quickly to the surrounding environment. B Insulation increases the flow of heat through the material. C Insulation traps air pockets which act as a barrier to the flow of heat. D Insulation absorbs heat and releases it slowly over time.

2. What are some common materials used for insulation?

A paper, rubber, leather, and fabric B plastic, metal, wood, and glass C fiberglass, foam, cellulose, and mineral wool D concrete, asphalt, brick, and stone

3. What is specific heat and how is it different from heat capacity?

A Specific heat measures the heat required to lower the temperature of a unit mass, while heat capacity measures the heat required to raise the temperature of an entire object. B Specific heat and heat capacity are the same thing and can be used interchangeably. C Specific heat measures the heat required to raise the temperature of an entire object, while heat capacity measures the heat required to raise the temperature of a unit mass. D Specific heat measures the heat required to raise the temperature of a unit mass, while heat capacity measures the heat required to raise the temperature of an entire object.

4. How does specific heat affect the temperature change of a substance?

A It determines how much heat energy is required to raise the temperature of the substance. B It only affects the color of the substance C It causes the substance to cool down faster D It has no effect on the temperature change

5. What is the role of conduction in the process of cooking?

A Conduction helps in the transfer of taste from the ingredients to the food. B Conduction helps in the transfer of heat from the cooking utensil to the food. C Conduction helps in the transfer of color from the ingredients to the food. D Conduction has no role in the process of cooking.

6. What is the principle behind the working of a refrigerator?

A The principle of radiation is used in the working of a refrigerator. B The principle of conduction is used in the working of a refrigerator. C The principle of convection is used in the working of a refrigerator. D The principle of insulation is used in the working of a refrigerator.

7. How does a thermos flask prevent heat transfer?

A A thermos flask prevents heat transfer by conduction. B A thermos flask prevents heat transfer by convection. C A thermos flask prevents heat transfer by radiation. D A thermos flask prevents heat transfer by all three methods: conduction, convection, and radiation.

8. If you were to roast chestnuts over an open fire, what type of heat transfer is roasting the chestnuts?

A Conduction B Convection C Radiation

9. In this famous scene in "Home Alone", one of the wet bandits is hit in the face with a hot clothing iron. What type of heat transfer burned his face?

A Conduction B Radition C Convection

10. In this scene from "Home Alone", Kevin heats a door knob. What type of heat transfer is Kevin using?

A Radition B Conduction C Convection