An ideal gas is taken through the cycle `A rarr B rarr C rarr A`, as shown in the figure. If the net heat supplied to the gas in the cycle is 5 J, what is the work done by the gas in the process `C rarr A`

Explanation

`Delta W_(AB)=PDeltaV=(10)(2-1)=10J`
`DeltaW_(BC)=0` (as v=constant)
from first law of thermodynamics
`DeltaQ=DeltaW+DeltaU`
`DeltaU=0` (process ABCA is cyclic)
` :. DeltaQ=DeltaW_(AB)-Delta_(BC)=5-10-0=-5J`