Mechanical Engineering

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.

Question: The capillary tube is not used in large capacity refrigeration systems because
[A].

cost is too high

[B].

capacity control is not possible

[C].

it is made of copper

[D].

required pressure drop can not be achieved

Answer: Option B

Explanation:

No answer description available for this question.

Question: The capillary tube, as an expansion device, is used in
[A].

domestic refrigerators

[B].

water coolers

[C].

room air conditioners

[D].

all of these

Answer: Option D

Explanation:

No answer description available for this question.

Question: In a refrigeration system, the expansion device is connected between the
[A].

compressor and condenser

[B].

condenser and receiver

[C].

receiver and evaporator

[D].

evaporator and compressor

Answer: Option C

Explanation:

No answer description available for this question.

Question: An evaporator is also known as
[A].

freezing coil

[B].

cooling coil

[C].

chilling coil

[D].

all of these

Answer: Option D

Explanation:

No answer description available for this question.