Q.

One mole of a monatomic ideal gas undergoes the cyclic process JKLMJ, as shown in the P-T diagram.

Match the quantities mentioned in List-I with their values in List-II and choose the correct option. [R is the gas constant]                   [2024]

  List - I   List - II
(P) Work done in the complete cyclic process (1) RT0-4RT0ln2
(Q) Change in the internal energy of the gas in the process JK (2) 0
(R) Heat given to the gas in the process KL (3) 3RT0
(S) Change in the internal energy of the gas in the process MJ (4) -2RT0ln2
    (5) -3RT0ln2

 

1 P → 1; Q → 3; R → 5; S → 4  
2 P → 4; Q → 3; R → 5; S → 2  
3 P → 4; Q → 1; R → 2; S → 2  
4 P → 2; Q → 5; R → 3; S → 4  

Ans.

(2)

From given P-T diagram,

For process JK: Isobaric  W=nR(3T0-T0)=2RT0

and Δu=ncvΔT=n×3R2×2T0=3RT0

For process KL: Isothermal  W=-nR(3T0)ln2

W=-3RT0ln2

Δu=0  and  Q=-3RT0ln2

For process LM: Isobaric

W=nR(T0-3T0)=-2RT0

Δu=ncvΔT=n×3R2×(-2T0)=-3RT0

For process MJ: Isothermal

W=nRTln2=RT0ln2

Δu=0

And work done in the complete cyclic process,

Wnet=RT0ln2+2RT0-3RT0ln2-2RT0

=-2RT0ln2

So correct option is (2)