R & AC RK 3

Horse power per ton of refrigeration is ex-pressed as

• 4.75 /COP
• COP/4.75
• COP
• none of the above.

Refrigeration in acroplanes usually employs the following refrigerant

• CO₂
• Freon-11
• Freon-22
• Air

Domestic refrigerator working on vapour compression cycle uses the following type

• capillary tube
• expansion valve.
• manually operated valve
• electrically operated throttling valve

In vapour compression cycle the condition of refrigerant is superheated vapour

• after passing through the condenser
• Before passing through the condenser
• before entering the expansion valve
• before entering the compressor.

Domestic refrigerator working on vapour compressor cycle uses the following type of expansion device

• Electrically operated throttling valve
• Manually operated valve
• Thermostatic valve
• Capillary tube

In vapour compression cycle the condition of refrigerant is dry saturated vapour

• after passing through the condenser
• before passing through the condenser
• Before entering the compressor
• Before entering the expansion valve

Air refrigeration operates on

• Reversed Carnot cycle
• Rankine cycle
• Brayton cycle
• Erricson cycle

The boiling point of ammonia is

• 50°C
• -10°C
• 33°C
• -33°C

Air refrigeration cycle is used in

• Gas liquefaction
• Air conditioning
• Commercial refrigerators
• Domestic refrigerators

One ton of refrigeration is equal to the refrigeration effect corresponding to melt- ing of 1000 kg of ice

• 5 hours
• 24 hours
• 8 hours
• 11 hours