MCQs of Psychrometry (Applied Thermodynamics - 3161910)

Applied Thermodynamics (3161910) MCQs

MCQs of Psychrometry

Showing 31 to 40 out of 60 Questions

31.

Wet bulb temperature is the temperature of air recorded by a thermometer, when

(a)	it is not affected by the moisture present in the air
(b)	its bulb is surrounded by a wet cloth exposed to the air
(c)	the moisture present in it begins to condense
(d)	none of the above

32.

Which of the following statement is TRUE?

(a)	During sensible cooling of the air, both dry bulb and wet bulb temperatures decrease
(b)	During sensible cooling of the air, dry bulb temperature decreases but wet bulb temperature remains constant
(c)	During sensible cooling of the air, dry and wet bulb temperatures decrease but dew point temperature remains constant
(d)	Both A and C

33.

The relative humidity __________ as air gets drier.

(a)	increases
(b)	decreases
(c)	remains constant
(d)	can’t predict

34.

Which of the following psychrometric process used in the cooling tower?

(a)	Heating and dehumidification
(b)	Heating and humidification
(c)	Cooling and dehumidification
(d)	Cooling and humidification

35.

In case of sensible cooling of air, the coil efficiency is given by (where BPF = by-pass-factor)

(a)	BPF - 1
(b)	1 - BPF
(c)	BPF
(d)	1 + BPF

36.

When BPF of the cooling coil is 0.3, then its efficiency will be

(a)	0
(b)	1
(c)	0.7
(d)	0.5

37.

The by-pass factor for a cooling coil

(a)	increases with increase in velocity of air passing through it
(b)	decreases with increase in velocity of air passing through it
(c)	remains unchanged with increase in velocity of air passing through it
(d)	may increase or decrease with increase in velocity of air passing through it depending upon the condition of air entering

38.

In order to cool and dehumidify a stream of moist air, it must be passed over the coil at a temperature

(a)	which lies between the dry bulb and wet bulb temperatures of the incoming stream
(b)	which lies between the wet bulb and dew point temperatures of the incoming stream
(c)	which is lower than the dew point temperature of the incoming stream
(d)	of adiabatic saturation of incoming stream

39.

In a psychrometric process, the sensible heat added is 30 kJ/s and the latent heat added is 20 kJ/s. The sensible heat factor for the process will be

(a)	0.3
(b)	0.6
(c)	0.7
(d)	0.8

40.

It is desired to condition the outside air from 70% relative humidity and 45°C dry bulb temperature to 50% relative humidity and 25°C dry bulb temperature (room condition). The practical arrangement will be

(a)	dehumidification
(b)	cooling and humidification
(c)	cooling and dehumidification
(d)	dehumidification and pure sensible cooling

Showing 31 to 40 out of 60 Questions