Heat is the transfer of thermal energy from one body or region to another body or region. Heat is energy in the form of random motion of molecules. Heat transfer can lead to an exchange of thermal energy and transfer of energy by conduction, convection or radiation. Temperature gradient, physical properties of the body, and cross-section of the body are some of the factors that affect thermal conductivity.

Read more: Heat Transfer Thermal Conductivity

Important Heat Transfer Thermal Conductivity Questions with Answers

1. Heat absorption causes the molecules of that body to ______ excess energy.

1. Loose
2. Gain
3. Remain constant
4. None of the above

Answer: b) Gain

Explanation: When heat absorption takes place, molecules gain excess energy.

2. State true or false: Nuclear energy uses the heat developed by the atoms.

1. TRUE
2. FALSE

Answer: a) TRUE

Explanation: Heat generated by the atoms is used for the production of electricity in nuclear power plants.

3. Does heat transfer through conduction involve direct contact?

1. YES
2. NO

Answer: a) YES

Explanation: The transfer of heat that takes place between atoms and molecules in direct contact is known as conduction.

4. Heat transfer through electromagnetic waves is known as ______.

1. Radiation
2. Conduction
3. Convention
4. None of the options

Answer: a) Radiation

Explanation: In the process of radiation, the transfer of heat takes place through electromagnetic waves.

5. State true or false: Heat can be converted to another form of energy.

1. TRUE
2. FALSE

Answer: a) TRUE

Explanation: Heat can be converted to another form of energy. The best example is that heat is converted to mechanical energy in a motorised vehicle.

6. What is the SI unit of thermal conductivity?

The SI unit of thermal conductivity is Watts per meter-kelvin (W.m-1K-1).

7. What would be the thermal conductivity of gold at 20 degrees celsius?

1. 218
2. 35
3. 90
4. 315

Answer: d) 315

Answer: The thermal conductivity of gold at 20 degrees celsius is 315.

8. Which among the following has high electrical conductivity and high thermal conductivity?

1. Plastic
2. Water
3. Wood
4. Metal

Answer: d) Metal

Explanation: Among the above options, metals display high electrical conductivity and high thermal conductivity.

9. The vibrations of molecules or atoms ______ when the temperature of the body increases.

1. Increase
2. Remains constant
3. Decrease
4. Becomes zero

Answer: a) Increase

Explanation: When the temperature of a body increases, the vibrations of molecules or atoms also increase.

10. The physical quantity which describes the direction and rate of the temperature change around a particular location is known as ______.

1. Thermal equilibrium
2. Isothermal property
3. Temperature gradient
4. Temperature quotient

Answer: c) Temperature gradient

Explanation: Temperature gradient defines the direction and rate of the temperature change around a particular location.

Learn more about Convection

Practice Questions

1. Define temperature and the scales to measure temperature.
2. What is meant by the term thermal conductivity?
3. What are the factors affecting thermal conductivity?
4. Define temperature gradient.
5. What are the means of heat transfer?