Question

A gas is taken through the cycle $A\to B\to C\to A,$ as shown. What is the net work done by the gas?

• A. Zero
• B. -2000 J
• C. 2000 J
• D. 1000 J

Answer 1

Answer: (D)

In a cyclic process, work done is equal to the area under the cycle and is positive if the cycle is clockwise and negative if the cycle is anticlockwise.

$\therefore$ The network done by the gas is
$W=$ Area of the cycle $ABCA$
$=\frac{1}{2}\times (7-2)\times 10^{-3}\times (6-2)\times 10^5$
$=\frac{1}{2}\times (5)\times 10^{-3}\times 4\times 10^5$
$=10\times 10^{2}J=1000J$