# Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning

### Exercise :: Heat Transfer, Refrigeration and Air Conditioning - Section 2

21.

Free convection flow depends on

 A. density B. coefficient of viscosity C. gravitational force D. all of these

Explanation:

No answer description available for this question. Let us discuss.

22.

The critical pressure of a liquid is the pressure

 A. above which a liquid will remain a liquid B. above which a liquid will explode C. above which a liquid will always convert into a vapour D. below which a liquid will always be in vapour form

Explanation:

No answer description available for this question. Let us discuss.

23.

Conduction is a process of heat transfer

 A. from one particle of the body to another without the actual motion of the particles B. from one particle of the body to another by the actual motion of the heated particles. C. from a hot body to a cold body, in a straight line, without affecting the intervening medium D. none of the above

Explanation:

No answer description available for this question. Let us discuss.

24.

Thermal diffusivity of a substance is

 A. directly proportional to the thermal conductivity B. inversely proportional to density of substance C. inversely proportional to specific heat D. all of the above

Explanation:

No answer description available for this question. Let us discuss.

25.

The sensible heat factor during the heating and humidification process is given by (where h1 = Enthalpy of air entering the heating coil, h2 = Enthalpy of air leaving the heating coil, and hA = Enthalpy of air at the end of humidification process)

 A. B. C. D.

Explanation:

No answer description available for this question. Let us discuss.