Heat Transfer Refrigeration and Air Conditioning MCQ with Answers

16) The optimum effective temperature for human comfort is

Answer is:

lower in winter than in summer

17) The wet bulb temperature lines, on the psychrometric chart, are curved lines.

Answer is:

Incorrect

18) Thermal diffusivity is a

Answer is:

physical property of a substance

19) The condition of refrigerant after leaving the compressor and before entering the condenser is superheated vapour.

Answer is:

Yes

20) The total radiation from a black body per second per unit area is __________ fourth power of the absolute temperature. This statement is known as Stefan-Boltzmann law.

Answer is:

directly proportional to

Explanation:

According to Stefan's law, the total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature. Stefan Boltzmann law is applicable for heat transfer by radiation.