Question

A black body is at a temperature of $5760K$. The energy of radiation emitted by the body at wavelength $250nm$ is $U_1$, at wavelength $500nm$ is $U_2$ and that at $1000nm$ is $U_3$. Wein's constant, $b=2.88\times {10}^{6}nmK$. Which of the following is correct?

• A. $U_1>U_2$
• B. $U_3=0$
• C. $U_2>U_1$
• D. $U_1=0$

Answer 1

The correct option is C $U_2>U_1$

Formula used ${\lambda }_m\propto \frac{1}{T}$

Given,

$T=5760K$

Maximum amount of emitted radiation corresponding to ${\lambda }_m=\frac{b}{T}$

${\lambda }_m=\frac{2.88\times {10}^{6}nmK}{5760K}=500nm$

So, $U_2$ is maximum.