Q. In an isothermal process the volume of an ideal gas is halved. One can say that
A) Internal energy of the system decreases
B) Work done by the gas is positive
C) Work done by the gas is negative
D) Internal energy of the system increases
Explanation
(c) For isothermal process
$dU = 0$ and work done $= dW = P\lbrack(V_{2} - V_{1})$
$\because V_{2} = \frac{V_{1}}{2} = \frac{V}{2}\ \therefore dW = - \frac{PV}{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.