Q. The quantities of heat required to raise the temperatures of two copper spheres of radii $r_{1}\ and\ r_{2}\ (r_{1} = 1.5r_{2})$ through 1 K are in the ratio of
A) 1
B) $\frac{3}{2}$
C) $\frac{9}{4}$
D) $\frac{27}{8}$
Explanation
(c) Heat required is proportional to square of radius
$\frac{Q_{1}}{Q_{2}} = \frac{r_{1}^{2}}{r_{2}^{2}} = \frac{(1.5)^{2}}{(1)^{2}} = \frac{9}{4}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.