Q. In a closed container, a liquid is stirred with a paddle to increase the temperature. Which of the following is true?
A) $\mathrm{\Delta}E = W \neq 0,q = 0$
B) $\mathrm{\Delta}E = W = q \neq 0$
C) $\mathrm{\Delta}E = 0,W = q \neq 0$
D) $W = 0,\ \mathrm{\Delta}E = q \neq 0$
Explanation
(a)
$\mathrm{\Delta}E = q + W$
$q$=0
($\because$ Temperature is to be increase, no heat should enter or leave the system)
$\mathrm{\Delta}E = q + W = 0 + W\ \ or\ \ \ \mathrm{\Delta}E = W$
$\therefore$ $W \neq 0,\ q = 0$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.