Heat Transfer MCQs

Question 1

Temperature of steam at around 540°C can be measured by

Accepted Answer

Thermocouple

Answer

Thermometer

Answer

Thermistor

Answer

Thermopile

Question 2

If the temperature of a solid surface changes form 27°C to 627°C, then its emissive power changes in the ratio of

Accepted Answer

81

Answer

3

Answer

9

Answer

27

Question 3

The amount of heat flow through a body by conduction is

Accepted Answer

All of the above

Answer

Directly proportional to the surface area of the body

Answer

Dependent upon the material of the body

Answer

Inversely proportional to the thickness of the body

Question 4

Which of the following has least value of conductivity

Accepted Answer

Air

Answer

Glass

Answer

Plastic

Answer

Rubber

Question 5

Depending on the radiating properties, body will be transparent when

Accepted Answer

ρ = 0, τ = 1 and α = 0

Answer

ρ = 0, τ = 0 and α = 1

Answer

ρ = 1, τ = 0 and α = 0

Answer

τ = 0, α+ρ = 1

Question 6

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

Accepted Answer

All of the above

Answer

Composition

Answer

Porosity

Answer

Structure

Question 7

The ratio of heat flow Q1/Q2 from two walls of same thickness having their thermal conductivities as K1 = 2K2 will be

Accepted Answer

2

Answer

1

Answer

0.5

Answer

0.25

Question 8

Sensible heat is the heat required to

Accepted Answer

Increase the temperature of a liquid of vapor

Answer

Change vapor into liquid

Answer

Change liquid into vapor

Answer

Convert water into steam and superheat it

Question 9

Thermal diffusivity of a substance is

Accepted Answer

Proportional of thermal conductivity (k)

Answer

Inversely proportional to (k)2

Answer

Proportional to (k)2

Answer

None of the above