Refrigeration & Air Conditioning MCQ Questions Mechanical Engineering


11) Large sized industrial air-conditioning plant are

a) Air cooled

b) Ground cooled

c) Water Cooled

d) Ammonia cooled

View Answer
Option – c)

12)Clapeyron equation is a relation between

(a) temperature, pressure and enthalpy

(b) specific volume and enthalpy

(c) temperature and enthalpy

(d) temperature, pressure, and specil volume

(e) temperature, pressure, specific volur and’enthalpy.

Ans: e


13) Which one of the following refrigerants has the highest critical temperature ?

a) Water

b) Carbon dioxide

c) Freon 12

d) Ammonia

View Answer
Option – a)

14)The boiling point of ammonia is

(a) 100° C

(b) 50° C

(c) 33.3° C

(d) 0°C

Ans: c


15) The correct nomenclature for ethylene is

a) R 150

b) R 740

c) R 1150

d) R 12

View Answer
Option – a)

16) When there is leakage of ammonia refrigerant, the sulphur stick gives

a) red smoke

b) blue smoke

c) white smoke

d) black smoke

View Answer
Option – c)

17) The recommemnded material use with Ammonia as a refrigerants is

a) Copper

b) Aluminium

c) Steel

d) Brass

View Answer
Option – c)

18)In milk chilling plants, the usual secondary refrigerant is

a) Ammonia solution

b) Sodium silicate

c) Glycol

d) Brine

View Answer
Option – d)

19) An evaporator is also known as

a) freezing coil

b) cooling coil

c) chilling coil

d) all of these

View Answer
Option – d)

20) Which of the following factor does not affect the condenser capacity ?

a) Material

b) Contact area

c) Temperature difference

d) Rate of natural convection

View Answer
Option – d)

21) Indication of amount of moisture in air is given by

a) DBT

b) WBT

c) DPT

d) Saturation temperature

View Answer
Option – b)

22) The mass of water vapour in one m3 of dry air is defined as

a) Specific humidity

b) Humidity ratio

c) Absolute humidity

d) Relative humidity

View Answer
Option – c)

23) The wet bulb depression is zero, when relative humidity is equal to

a) zero

b) 0.5

c) 0.75

d) 1.0

View Answer
Option – d)

24) The heat production from a normal healthy mass when asleep is about

a) 45 W

b) 20 W

c) 60 W

d) 70 W

View Answer
Option – c)

25) The human body feeds comfortable when the heat stored in the body is

a) Positive

b) Negative

c) Zero

d) Either zero or negative

View Answer
Option – c)

26)  The aspect ratio, for rectangular ducts, should not be greater than …….. in any case

a) 8

b) 10

c) 12

d) 16

View Answer
Option – a)

27) A duct is said to be a low velocity duct if the velocity of air in the duct is upto

a) 600 m/min

b) 800 m/min
c) 1200 m/min

d) 1600 m/min

View Answer
Option – a)