Question

The internal energy of a gas is given by $U=2 P V$. It expands from $V_{0}$ to $2 V_{0}$ against a constant pressure $P_{0}$. The heat absorbed by the gas in the process is :

• A. $2 P_{0} V_{0}$
• B. $4 P_{0} V_{0}$
• C. $3 P_{0} V_{0}$
• D. $P_{0} V_{0}$

Answer 1

Answer: (C)

$W =P_{0} \Delta V=P_{0} V_{0}$
and $\Delta U =2 P_{0}\left(2 V_{0}-V_{0}\right)=2 P_{0} V_{0}$
$\Rightarrow Q =W+\Delta U=3 P_{0} V_{0}$