251. Planck’s law holds good for all coloured bodies.
TRUE
FALSE
✅ The correct answer is option A.
Heat Transfer, Refrigeration and Air Conditioning MCQs
252. The inclined and non-uniformly spaced straight lines on a psychrometric chart indicates wet bulb temperature.
Agree
Disagree
✅ The correct answer is option A.
253. When there is an addition of water vapour to the air of enclosed space, a gain in __________ is said to occur.
sensible heat
latent heat
✅ The correct answer is option B.
254. The condition of refrigerant after passing through the condenser in a vapour compression system is
saturated liquid
wet vapour
dry saturated vapour
superheated vapour
✅ The correct answer is option A.
255. The desirable property of a refrigerant is
low boiling point
high critical temperature
high latent heat of vaporisation
all of these
✅ The correct answer is option D.
256. Dry bulb temperature is the temperature of air recorded by a thermometer, when
it is not affected by the moisture present in the air
its bulb is surrounded by a wet cloth exposed to the air
the moisture present in it begins to condense
none of the above
✅ The correct answer is option A.
257. Most thermostatic expansion valves are set for a superheat of
5°C
10°C
15°C
20°C
✅ The correct answer is option A.
258. The human body feels comfortable when the heat stored in the body is
positive
negative
zero
none of these
✅ The correct answer is option C.
259. According to Newton’s law of cooling, the heat transfer from a hot body to a cold body is
directly proportional to the surface area
directly proportional to the difference of temperatures between the two bodies
either (a) or (b)
both (a) and (b)
✅ The correct answer is option D.
260. The relative humidity lines on a psychrometric chart are
vertical and uniformly spaced
horizontal and uniformly spaced
horizontal and non-uniformly spaced
curved lines
✅ The correct answer is option D.