Question

For an enclosure maintained at 2000K, the maximum radiation occurs at wavelength ${\lambda }_m$. If the temperature is raised to 3000 K, the peak will shift to

• A. $\frac{3}{2}\lambda m$
• B. $0.5{\lambda }_m$
• C. ${\lambda }_m$
• D. $\frac{2}{3}\lambda m$

Answer 1

The correct option is D

$\frac{2}{3}\lambda m$

According to Wein’s law

$\lambda \alpha \frac{1}{T}$

$\frac{{\lambda }_2}{{\lambda }_1}=\frac{T_1}{T_2}$

$\frac{{\lambda }_2}{{\lambda }_m}=\frac{2000}{3000}$

$\Rightarrow {\lambda }_2=\frac{2\lambda m}{3}$