Q163 / 200 · Manipal (MET) 2012 · Physics
Work done by air when it expands from 50 L to 150 L at a constant pressure of 2 atmosphere is
- Correct answerA$2 \times 10^4 \mathrm{~J}$
- B$2 \times 100 \mathrm{~J}$
- C$2 \times 10^{11} \mathrm{~J}$
- D$2 \times 10^{15} \mathrm{~J}$
Solution
Work done
$\begin{gathered}
W=p\left(V_2-V_1\right) \\
\text { Given, } p=2 \times 10^5 \mathrm{~N} / \mathrm{m}^2, V_1=50 \times 10^{-3} \mathrm{~m}^3 \\
V_2=150 \times 10^{-3} \mathrm{~m}^3 \\
\therefore \quad W=2 \times 10^5(150-50) 10^{-3} \\
W=2 \times 10^5 \times 100 \times 10^{-3} \\
W=2 \times 10^4 \mathrm{~J}
\end{gathered}$
Hence, the correct answer is option: 'A'.