Q.
A black body radiates energy at the rate of $E\ Wm^{- 2}$ at a high temperature$\ T\ K$. When the temperature is reduced to $\left( \frac{T}{2} \right)$ K, the radiant energy is
A) $\frac{E}{2}$
B) $2E$
C) $\frac{E}{4}$
D) $\frac{E}{16}$
Explanation
(d) According to Stefan’s law,
$E \propto T^{4}$
or $\frac{E_{2}}{E_{1}} = \left( \frac{T_{2}}{T_{1}} \right)^{4}$
or $\frac{E_{2}}{E} = \left( \frac{\frac{T}{2}}{T} \right)^{4} = \left( \frac{1}{2} \right)^{4}$
or $E_{2} = \frac{E}{16}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.