Question

Heat absorbed by a system in going through a cyclic process shown in figure is

• A. $10^{7}\pi J$
• B. $10^{6}\pi \text{J}$
• C. $10^{2}\pi \text{J}$
• D. $10^{4}\pi \text{J}$

Answer 1

Answer: (C)

We know that,

$\Delta u=0$ in cyclic process

So $\Delta Q=\Delta u+\Delta w$

$\Delta Q=\Delta w$

We know,

work done = Area under P-V curve

= Area of circle

$=\frac{\pi r^{2}}{4}$

$=\frac{\pi }{4}\times \left(\right.30-10\left.\right)\times 10^{3}\left(\right.30-10\left.\right)\times 10^{- 3}$

$=\frac{\pi }{4}\times 20\times 20$

$=\frac{\pi }{4}\times 400$

$=100\pi $

$=10^{2}\pi \text{J}$

So Heat energy absorbed

$\Delta Q=\Delta w$

$=10^{2}\pi J$