Heat Transfer Refrigeration and Air Conditioning MCQ with Answers

Heat Transfer Refrigeration and Air Conditioning MCQ with Answers

296) Which of the following refrigerant is highly toxic and flammable?

Answer is:

Ammonia

297) The unit of Stefan-Boltzman constant is

Answer is:

Watt/m²K⁴

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. The unit of Stefan-Boltzman is Watt/m²K⁴.

298) The emissive power of a body depends upon its

Answer is:

all of these

Explanation:

The emissive power of a body depends upon its
* temperature
* physical nature
* wave length

299) An electric cable of aluminium conductor (k = 240 W/mK) is to be insulated with rubber (k = 0.15 W/mK). The cable is to be located in air (h = 6 W/m²). The critical thickness of insulation will be

Heat Transfer Refrigeration and Air Conditioning MCQ with Answers

296) Which of the following refrigerant is highly toxic and flammable?

Ammonia

297) The unit of Stefan-Boltzman constant is

Watt/m²K⁴

298) The emissive power of a body depends upon its

all of these

299) An electric cable of aluminium conductor (k = 240 W/mK) is to be insulated with rubber (k = 0.15 W/mK). The cable is to be located in air (h = 6 W/m²). The critical thickness of insulation will be

25 mm

300) The dehumidification process, on the psychrometric chart, is shown by

vertical line

296) Which of the following refrigerant is highly toxic and flammable?

Ammonia

297) The unit of Stefan-Boltzman constant is

Watt/m2K4

298) The emissive power of a body depends upon its

all of these

299) An electric cable of aluminium conductor (k = 240 W/mK) is to be insulated with rubber (k = 0.15 W/mK). The cable is to be located in air (h = 6 W/m2). The critical thickness of insulation will be

25 mm

300) The dehumidification process, on the psychrometric chart, is shown by

vertical line

Watt/m²K⁴

299) An electric cable of aluminium conductor (k = 240 W/mK) is to be insulated with rubber (k = 0.15 W/mK). The cable is to be located in air (h = 6 W/m²). The critical thickness of insulation will be