Q.

Consider two containers A and B containing monoatomic gases at the same pressure (P), volume (V) and temperature (T). The gas in A is compressed isothermally to 18 of its original volume, while the gas in B is compressed adiabatically to 18 of its original volume. The ratio of final pressure of gas in B to that of gas in A is:      [2023]

1 8  
2 81/2  
3 18  
4 4  

Ans.

(4)

Isothermal process, T=constant

PV=nRT=constant

P1V1=P2V2

PV=PA(V8)

PA=8P

Adiabatic process, PVγ=constant

γ for monoatomic gas is 53

P1V1γ=P2V2γ

PBP=(V1V2)γ=(VV/8)5/3

PB=32P

PBPA=32P8P=4