Q.
An ideal monoatomic gas is taken through the thermodynamic states $A \rightarrow B \rightarrow C \rightarrow D$ via the paths shown in the figure. If $U_{A},U_{B}{,U}_{C}$ and $U_{D}$ represent the internal energy of the gas in states $A,B,C$ and $D$ respectively, then which of the following is not true
A) $U_{A} = U_{D}$
B) $U_{B} < U_{A}$
C) $U_{B} = U_{C}$
D) $U_{C} > U_{D}$
Explanation
(b) Internal energy of a gas is
$U = \frac{3}{2}nRT$
For a given number of moles of the same gas, $U$ depends only $T$
Therefore $U_{B}$ at $2T < U_{A}$ at temperature $T$ is a wrong statement
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.