Q. Calculate change in internal energy of a system which has absorbed 2 kcal of heat and done 500 J of work
A) 7900 J
B) 8900 J
C) 6400 J
D) 5400 J
Explanation
(a) $dQ = 2kcal = 200cal = 2000 \times 4.2\ J = 8400\ J$
$dW = 500\ J$,
$dU = dQ - dW$
$= 8400 - 500 = 7900\ J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.