### Q.9:- A thermodynamic system is taken from an original state to an intermediate state by the linear process shown in Fig. (12.13).

### Its volume is then reduced to the original value from E to F by an isobaric process. Calculate the total work done by the gas from D to E to F.

**Answer:-**Total work done by the gas from D to E to F = Area of ΔDEF

Area of ΔDEF = (1/2) DE × EF

Where,

DF = Change in pressure

= 600 N/m^{2} – 300 N/m^{2}

= 300 N/m^{2}

FE = Change in volume

= 5.0 m^{3} – 2.0 m^{3}

= 3.0 m^{3}

Area of ΔDEF = (1/2) × 300 × 3 = 450 J

Therefore, the total work done by the gas from D to E to F is 450 J.