Heat Transfer Multiple Choice Questions and Answers

1. Thermal diffusivity is

1. a dimensionless parameter
2. function of temperature
3. used as mathematical model
4. a physical property of the material

2. Which of the following has maximum value of thermal conductivity

1. aluminium
2. steel
3. brass
4. copper

3. Which of the following is the case of heat transfer by radiation

1. blast furnace
2. heating of building
3. cooling of parts in furnace
4. heat received by a person from fireplace

4. Sensible heat is the heat required to

1. change vapour into liquid
2. change liquid into vapour
3. increase the temperature of a liquid of vapour
4. convert water into steam and superheat it

5. Total heat is the heat required to

1. change vapour into liquid
2. change liquid into vapour
3. increase the temperature of a liquid or vapour
4. convert water into steam and superheat it

6. Thermal conductivity of glass-wool varies from sample to sample because of variation in

1. composition
2. density
3. porosity
4. all of the above.

7. When heat is transferred from one particle of hot body to another by actual motion of the heated particles, it is referred to as heat transfer by

1. conduction
2. convection
3. radiation
4. conduction and convection

8. When heat is transferred form hot body to cold body, in a straight line, without affecting the intervening medium, it is referred as heat transfer by

1. conduction
2. convection
3. radiation
4. conduction and convection

9. When heat is Transferred by molecular collision, it is referred to as heat transfer by

1. conduction
2. convection
3. radiation
4. scattering

10. Heat transfer in liquid and gases takes place by

1. conduction
2. convection
3. radiation
4. conduction and convection