Q.

The volume of an ideal gas (γ=1.5) is changed adiabatically from 5 litres to 4 litres. The ratio of initial pressure to final pressure is:           [2024]

1 45  
2 1625  
3 855  
4 25  

Ans.

(3)   

        For adiabatic process, PVγ=k

         P1V13/2=P2V23/2

          P1×(5)3/2=P2×(4)3/2

          P1P2=(45)3/2=(2)3(125)1/2=855