Frost formation on the evaporator tubes in the domestic refrigerators

The bank of tubes located at the back of the domestic refrigerators are the __________ tubes.

A

Refrigerant cooling

B

Evaporator

C

Condenser

D

Throttling

If a truck can carry 10 to 16 boxed refrigerators, then what is the least number of refrigerators that 4 trucks can carry?

A

40

B

52

C

48

D

64

Formation of frost on evaporator in refrigerator

A

Results in loss of heat due to poor heat transfer

B

Increases heat transfer rate

C

Is immaterial

D

Can be avoided by proper design

The evaporator used in household refrigerators is

A

Frosting evaporator

B

Non-frosting evaporator

C

Defrosting evaporator

D

None of these

Most of the domestic refrigerators work on the following refrigeration system

A

Vapour compression

B

Vapour absorption

C

Carnot cycle

D

Electrolux refrigerator

Refrigerants commonly used for domestic refrigerators are

A

Ethyl chloride or methyle chloride

B

Freon-12

C

Propane

D

NH₃ or CO₂

The formation of frost on cooling coils in a refrigerator

A

Increases heat transfer

B

Improves C.O.P. of the system

C

Increases power consumption

D

Reduces power consumption

The diameters of fire tubes and superheater tubes in locomotive boiler are

A

47.5 mm, 130 mm

B

32.5 mm, 180 mm

C

65.5 mm, 210 mm

D

24.5 mm, 65 mm

Brass tubes are used in the manufacture of tubes of evaporators used in sugar and salt industries, mainly because of its

A

High co-efficient of thermal expansion

B

Low thermal conductivity

C

High corrosion resistance

D

All of the above

In a shell and tube heat exchanger for a given heat transfer surface area, smaller diameter tubes are favoured as compared to larger diameter ones ; because the smaller diameter tubes

A

Are easier to clean

B

Are less prone to fouling

C

Can be fitted into a smaller shell diameter hence the cost of the heat exchanger would be less

D

None of these

Frost formation on the evaporator tubes in the domestic refrigerators

Related Questions