Q. If 150 J of heat is added to a system and the work done by the system is 110 J, then change in internal energy will be
A) 40 J
B) 110 J
C) 150 J
D) 260 J
Explanation
(a) From the first law of thermodynamics
We have, $Q = \mathrm{\Delta}U + W$
$\mathrm{\Delta}U = Q - W$
$\mathrm{\Delta}U = 150 - 110 = 40J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.