Efficiency of a Carnot engine is given as 80%. If the- cycle direction be reversed, what will be the value of COP of reversed Carnot cycle_________________?

A. 1.25
B. 0.8
C. 0.5
D. 0.25

Aqua ammonia is used as refrigerant in the following type of refrigeration system_________________?

A. Compression
B. Direct
C. Indirect
D. Absorption

If a heat pump cycle operates between the condenser temperature of +27°C and evaporator temperature of – 23°C, then the Carnot COP will be_________________?

A. 0.2
B. 1.2
C. 5
D. 6

In a refrigeration cycle, the flow of refrigerant is controlled by___________________?

A. Compressor
B. Condenser
C. Evaporator
D. Expansion valve

The lower horizontal line of the refrigeration cycle plotted on pressure-enthalpy-diagram represents_____________________?

A. Condensation of the refrigerant vapour
B. Evaporation of the refrigerant liquid
C. Compression of the refrigerant vapour
D. Metering of the refrigerant liquid

Freon group of refrigerants are___________________?

A. inflammable
B. D. toxic
C. non-inflammable and toxic
D. non-toxic and inflammable

In vapour compression cycle using NH3 as refrigerant, initial charge is filled at_________________?

A. Suction of compressor
B. Delivery of compressor
C. High pressure side close to receiver
D. Low pressure side near receiver

On the pressure-enthalpy diagram, condensation and desuperheating is represented by a horizontal line because the process ________________?

A. involves no change in volume
B. takes place at constant temperature
C. takes place at constant entropy
D. takes place at constant enthalpy

The leaks in a refrigeration system using Freon are detected by____________________?

A. Halide torch which on detection produces greenish flame lighting
B. Sulphur sticks which on detection gives white smoke
C. Using reagents
D. Smelling

Moisture in freon refrigeration system causes________________?

A. Ineffective refrigeration
B. High power consumption
C. Freezing automatic regulating valve
D. Corrosion of whole system