Refrigeration and Air Conditioning

Question: For unsaturated air, the dew point temperature is __________ wet bulb temperature.
[A].

equal to

[B].

less than

[C].

more than

Answer: Option B

Explanation:

No answer description available for this question.

Question: Dew point temperature is the temperature of air recorded by a thermometer, when the moisture present in it begins to condense.
[A].

Correct

[B].

Incorrect

Answer: Option A

Explanation:

No answer description available for this question.

Question: Dry 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

Answer: Option A

Explanation:

No answer description available for this question.

Question: In a saturated air-water vapour mixture, the
[A].

dry bulb temperature is higher than wet bulb temperature

[B].

dew point temperature is lower than wet bulb temperature

[C].

dry bulb, wet bulb and dew point temperature are same

[D].

dry bulb temperature is higher than dew point temperature

Answer: Option C

Explanation:

No answer description available for this question.

Question: Degree of saturation or percentage humidity is
[A].

the mass of water vapour present in 1 m3 of dry air

[B].

the mass of water vapour present in 1 kg of dry air

[C].

the ratio of the actual mass of water vapour in a unit mass of dry air to the mass of water vapour in the same mass of dry air when it is saturated at the same temperature and pressure.

[D].

the ratio of actual mass of water vapour in a given volume of moist air to the mass of water vapour in the same volume of saturated air at the same temperature and pressure

Answer: Option C

Explanation:

No answer description available for this question.

Question: A mixture of dry air and water vapour, when the air has diffused the maximum amount of water vapour into it, is called
[A].

dry air

[B].

moist air

[C].

saturated air

[D].

specific humidity

Answer: Option C

Explanation:

No answer description available for this question.

Question: If a gas is to be liquified, its temperature must be
[A].

increased to a value above its critical temperature

[B].

reduced to a value below its critical temperature

[C].

equal to critical temperature

[D].

none of the above

Answer: Option C

Explanation:

No answer description available for this question.

Question: Most thermostatic expansion valves are set for a superheat of
[A].

5°C

[B].

10°C

[C].

15°C

[D].

20°C

Answer: Option A

Explanation:

No answer description available for this question.

Question: A valve which maintains a constant degree of superheat at the end of the evaporator coil, is called
[A].

automatic expansion valve

[B].

high side float valve

[C].

thermostatic expansion valve

[D].

low side float valve

Answer: Option D

Explanation:

No answer description available for this question.

Question: A thermostatic expansion valve in a refrigeration system
[A].

ensures the evaporator completely filled with refrigerant of the load

[B].

is suitable only for constant load systems

[C].

maintains different temperatures in evaporator in proportion to load

[D].

none of the above

Answer: Option A

Explanation:

No answer description available for this question.