Q.

An ideal monoatomic gas of n moles is taken through a cycle WXYZW consisting of consecutive adiabatic and isobaric quasi-static processes, as shown in the schematic V-T diagram. The volume of the gas at W, X and Y points are 64 cm3, 125 cm3 and 250 cm3, respectively. If the absolute temperature of the gas TW at the point W is such that nRTW=1 J (R is the universal gas constant), then the amount of heat absorbed (in J) by the gas along the path XY is ______.              [2025]


Ans.

(1.6)

Qxy=P1(Vy-Vx)+nR(Ty-Tx)32

Qxy=52R(Ty-Tx)n

Tw·(64)23=Tx·(125)23

Tw·16=Tx·25

Tx=1625Tw

TyVy=TxVx

Ty=Tx(250125)=2Tx

Qxy=52nR(Tx)=52nR·1625Tw      [nRTw=1 J given]

  Qxy=85=1.6