Question

$3000J$ of heat is given to a gas at a constant pressure of $P=(2\times {10}^{5}N/m^2)$.
If its volume increases by 10 litres during the process, find the change in the internal energy of the gas.

• A. $1600J$
• B. $3000J$
• C. $2500J$
• D. $1000J$

Answer 1

The correct option is D $1000J$

Given:
$q=3000J$
$P=2\times {10}^{5}N/m^2$
$△V=10\times {10}^{-3}{m}^3$
So, the work done is given as,
$w=-P△V=-(2\times {10}^{5}N/m^2)(10\times {10}^{-3}{m}^3)=-2\times {10}^{3}J$

From the first law of thermodynamics,
$△U=q+w=3000-2000=1000J$