Class 7 (Science assignment)

 

Understanding Heat Energy

Heat energy is a form of energy that flows from a hotter object to a colder object. The Sun is the main natural source of heat energy for the Earth. We feel heat when energy is transferred to our bodies. Heat can travel in three ways: conduction, convection, and radiation. Conduction occurs mainly in solids, where heat moves through direct contact. Convection occurs in liquids and gases when warmer particles move upward and cooler particles move downward. Radiation transfers heat through waves and does not need a medium. Heat energy is used in cooking, heating homes, and many machines.

MCQs

1. Heat energy flows from:
a) Cold object to hot object
b) Hot object to cold object
c) Both directions equally
d) No direction

2. The main natural source of heat energy is:
a) Moon
b) Fire
c) Sun
d) Electricity

3. Heat transfer through direct contact is called:
a) Radiation
b) Convection
c) Conduction
d) Reflection

4. Conduction mainly occurs in:
a) Solids
b) Liquids
c) Gases
d) Vacuum

5. Convection occurs in:
a) Solids only
b) Liquids and gases
c) Metals only
d) Vacuum

6. Heat transfer through waves is called:
a) Conduction
b) Convection
c) Radiation
d) Evaporation

7. Radiation can travel through:
a) Only solids
b) Only liquids
c) Vacuum
d) Only gases

8. Which is an example of conduction?
a) Heating water in a pot
b) Feeling heat from the Sun
c) A metal spoon becoming hot in tea
d) Air movement in a room

9. Heat is a type of:
a) Matter
b) Energy
c) Force
d) Pressure

10. Heat transfer in liquids happens mainly by:
a) Convection
b) Radiation
c) Conduction only
d) Reflection