A thermodynamic system is taken through the cyclic `PQRSP` process. The net work done by the system is

Options

A. 20 J
B. - 20 J
C. 400 J
D. -374 J

Answer

B

Explanation

W = Area under P-V diagram
= `-(200-100)xx10^3 xx (300-100)xx10^(-6)`
= -20 J [-ve due to anticlockwise path]
Note: (i) For clockwise, `W rarr` +ve
(ii) For anticlockwise: `W rarr ` -ve.