Q.

If the process carried out on one mole of monatomic ideal gas is as shown in the TV-diagram with P0V0=13RT0, the correct match is,          [2019]

1 I → P, II → T, III → Q, IV → T  
2 I → S, II → T, III → Q, IV → U  
3 I → P, II → R, III → T, IV → P  
4 I → P, II → R, III → T, IV → S  

Ans.

(3)

I.  W1→2→3=W1→2+W2→3

=nRTln(VfVi)+P dV

=1RT03ln(2V0V0)+zero        [∵n=1, and W2→3 isochoric no change in volume⇒ΔV=0]

=RT03ln2                    ∴ I→P

II.  ΔU1→2→3=ΔU1→2+ΔU2→3

=0+nCvΔT=nf2RΔT          [Process 1→2 isothermal, ΔT=0]

=1×3R2(T0-T03)=RT0      [For monoatomic gas f=3]

∴  II→R

III.  Q1→2→3=W1→2→3+ΔU1→2→3

From first law of thermodynamics

=RT03ln2+RT0=RT03[ln2+3]

∴  III→T

IV.  Q1→2=W1→2+ΔU1→2

=RT03ln2+0=RT03ln2       [∵ΔU1→2=0]

∴  IV→P