Multiple Choice Questions on Vapour Compression Cycle

In a vapour compression cycle, the refrigerant enters the compressor as:

• Saturated liquid

• Wet vapour

• Superheated vapour

• Subcooled liquid

In an ideal vapour compression cycle, heat rejection takes place in the:

• Evaporator

• Condenser

• Compressor

• Expansion valve

The expansion device in a vapour compression cycle is usually a:

• Turbine

• Throttle valve

• Reciprocating piston

• Diffuser

In an ideal vapour compression cycle, compression is assumed to be:

• Isothermal

• Isobaric

• Adiabatic and reversible (isentropic)

• Polytropic

The main function of the evaporator is to:

• Reject heat

• Absorb heat from surroundings

• Compress refrigerant

• Expand refrigerant

The coefficient of performance (COP) of a vapour compression cycle is given by:

• Work input / Heat output

• Heat absorbed in evaporator / Work input

• Work output / Heat rejected

• Heat rejected / Work input

In a vapour compression cycle, subcooling of liquid refrigerant before expansion:

• Decreases COP

• Increases COP

• Has no effect

• Decreases refrigerating effect

In superheating of vapour before compression:

• COP decreases

• COP increases

• Refrigerating effect decreases

• No change occurs

Which component separates high-pressure and low-pressure sides in VCC?

• Evaporator

• Expansion valve

• Condenser

• Receiver

If isentropic efficiency of a compressor decreases, COP of the system:

• Increases

• Decreases

• Remains constant

• Becomes infinite