Q.

A sample of gas at temperature T is adiabatically expanded to double its volume. Adiabatic constant for the gas is γ=3/2. The work done by the gas in the process is (n = 1 mole)               [2024]

1 RT[1-22]  
2 RT[22-1]  
3 RT[2-2]  
4 RT[2-2]  

Ans.

(4)   

         PV=nRTP=nRTV

          Also, PVγ= constant

         nRTVVγ= constant TVγ-1= constant

          TVγ-1=T2·(2V)γ-1

           T2=T·(12)1/2=T2

            W=nR(T1-T2)γ-1=2nR(T-T2)=RT(2-2)