Q. The maximum energy in thermal radiation from a source occurs at the wavelength 4000$\mathring{\mathrm{A}}$. The effective temperature of the source is
A) 7325 K
B) 800 K
C) $10^{4}$ K
D) $10^{6}$ K
Explanation
(a) According to Wien’s displacement law
$\lambda_{m} = \frac{b}{T} \Rightarrow T = \frac{b}{\lambda_{m}} = \frac{2.93 \times 10^{- 3}}{4000 \times 10^{- 10}} = 7325$ K
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.