A fixed mass of oxygen gas performs a cyclic process ABCA as shown. Find the efficiency of the process.

Explanation

`A rarr B` isochoric
`W_(AB) = 0`
`Q_(AB) = nC_(V) (3 T_(A) - T_(A))`
`= ((5)/(2)) nR 2T_(A) = 5 nRT_(A)`
`W_(BC) = nRT_(A) 1n ((P_(B))/(P_(C ))) = 3 nRt_(A) 1n 3`
`= 3 nRT_(A) 1n 2 = Q_(BC)`
`W_(CA) = P (V_(A) - V_(C )) = nR (T_(A) - 3 T_(A)) = - 2 nRT_(A)`
Efficiency of a cyclic process is given by `eta`
`= ("Work d one in cyclic Process")/("Heat supplied to the system") = (W)/(Q_(i n)`
Efficiency `eta = (3 nRT_(A) 1n 3 - 2 nRT_(A))/(5 nRT_(A) + 3 nRT_(A) 1n 3) %`
`= (3 1n 3 - 2)/(5 + 3 1n 3)%`