Work Done In Thermodynamics

The work done during the expansion of a gas from a volume of to against a constant external pressure of atm is :-

The coefficient of performance of a refrigerator is . If the temperature inside freezer is the temperature of the surroundings to which it rejects heat is

The volume of a monatomic gas varies with its temperature , as shown in the graph. The ratio of work done by the gas, to the heat absorbed by it, when it undergoes a change from state to state , is