Helium gas goes through a cycle ABCDA (consisting of two isochoric and isobaric lines) as shown in figure Efficiency of this cycle is nearly: (Assume the gas to be close to ideal gas)

Options

A. 0.105
B. 0.125
C. 0.154
D. 0.091

Answer

C

Explanation

`Q_(AB)=nCv[(P_0V_0)/(R)],Q_(BC)=nCp[(2P_(0)V_(0))/(R)]`
`Q_(CD)=nCv[(2P_(0)v_(0))/(R)],Q_(DA)=nCp[(p_(0)V_(0))/(R)]`
`Q_(repeated)=Q_(0)+Q_(DA)`
`Q_(absorbed)=Q_(AB)+Q_(BC)`
`eta=1-(Q_(rej))/(Q_(ab))=0.154`