Question

The heat absorbed by the system in going through the cyclic process as shown in figure is

• A. $30.4J$
• B. $31.4J$
• C. $32.4J$
• D. $33.4J$

Answer 1

The correct option is B $31.4J$

In cyclic process, change in internal energy is zero,

$\Delta U=0$

From 1st law of thermodynamics,

$\Delta Q=\Delta U+\Delta W$

$\Delta Q=\Delta W$. . . . . . . . .(1)

Work done, $\Delta W=$Area under $V-P$ curve

$\Delta W=\frac{\pi }{4}\times (600-400)\times {10}^3\times (500-300)\times {10}^{-6}$

$\Delta W=\frac{3.14}{4}\times 200\times 200=3.14\times 10$

$\Delta W=31.4J$

From equation (1), heat observed by the system is

$\Delta Q=31.4J$

The correct option is B.