Heat Transfer MCQs

Question 1

The film co-efficient between condensing vapour and metal wall increases with

Accepted Answer

Increasing temperature of the vapour

Answer

Decreasing temperature of the vapour

Answer

Increasing viscosity of the film of condensate

Answer

Increasing temperature drop

Question 2

The main function of baffles provided in a shell and tube heat exchanger is to

Accepted Answer

Enhance turbulence

Answer

Facilitate the cleaning of outer tube surface

Answer

Hold the tubes in position

Answer

All of the above

Question 3

The maximum heat transfer co-efficient from steam heating will be attained when the steam is

Accepted Answer

Saturated

Answer

Supersaturated

Answer

Wet

Answer

None of these

Question 4

The rate of emission of radiation by a body does not depend upon the

Accepted Answer

Shape and porosity of the body

Answer

Wavelength of radiation

Answer

Surface temperature of the body

Answer

Nature of the surface

Question 5

In a multiple effect evaporator, the effect of boiling point elevation is to

Accepted Answer

Reduce the economy

Answer

Reduce the capacity

Answer

Increase the economy

Answer

None of these

Question 6

Which of the following is concerned with both heat and mass transfer?

Accepted Answer

Lewis relationship

Answer

Nusselt number

Answer

Kutateladze number

Answer

Froude number

Question 7

The ratio of kinematic viscosity to thermal diffusivity is called the __________ number.

Accepted Answer

Prandtl

Answer

Peclet

Answer

Stanton

Answer

Nusselt

Question 8

(NGr × NPr) is called the __________ number.

Accepted Answer

Reyleigh

Answer

Graetz

Answer

Nusselt

Answer

Stanton

Question 9

h.D/K is called the __________ number.

Accepted Answer

Nusselt

Answer

Peclet

Answer

Rayleigh

Answer

Grashoff