Question

In the diagram, the graph between volume and pressure for a thermodynamic process is shown. If $U_{A}=0$ , $U_{B}=20 \, J$ and the energy given from $B$ to $C$ is $30 \, J$ , then at the stage of $C$ , the internal energy of the system is

• A. $50 \, J$
• B. $60 \, J$
• C. $30 \, J$
• D. $10 \, J$

Answer 1

Answer: (A)

$W_{B C}=0$
$\therefore \, \, \Delta U_{B C}=\Delta Q$
$U_{C}-U_{B}=30$
$U_{C}-20=30$
$U_{C}=50 \, J$