Question

A gas expands from $1L$ to $3L$ at atmospheric pressure. The work done by the gas is about :

• A. $2J$
• B. $200J$
• C. $300J$
• D. $2{\times 10}^5$

Answer 1

Answer: (B)

$200J$

Change in volume, $dV=V_2-V_1=3litre-1litre=2litre=2\times {10}^{-3}{m}^3$

Pressure, $P=1atm={10}^{5}Pascal={10}^{5}N/m^2$

Work done by gas $=P\times dV$

$=2\times {10}^{-3}\times {10}^5=200J$