Q. A thermally insulated rigid container contains an ideal gas heated by a filament of resistance $100\ \Omega$ through a current of $1A$ for 5 min then change in internal energy is
A) $0\ kJ$
B) $10\ kJ$
C) $20\ kJ$
D) $30\ kJ$
Explanation
(d) Volume of the ideal gas is constant so $W = P\mathrm{\Delta}V = 0$
Using FLOT
$\mathrm{\Delta}Q = \mathrm{\Delta}U \Rightarrow \mathrm{\Delta}U = i^{2}Rt$
$= 1^{2} \times 100 \times 5 \times 60 = 30 \times 10^{3} = 30kJ$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.