Q. The maximum energy in the thermal radiation from a hot source occurs at a wavelength of $11 \times 10^{- 5}cm$. According to Wien’s law, the temperature of the source (on Kelvin scale) will be $n$ times the temperature of another source (on Kelvin scale) for which the wavelength at maximum energy is $5.5 \times 10^{- 5}cm$. The value $n$ is
A) 2
B) 4
C) $\frac{1}{2}$
D) 1
Explanation
(c) $\frac{T_{1}}{T_{2}} = \frac{\lambda_{m_{2}}}{\lambda_{m_{1}}} = \frac{5.5 \times 10^{5}}{11 \times 10^{5}} = \frac{1}{2} \Rightarrow n = \frac{1}{2}\ \lbrack Given\ T_{1} = nT_{2}\rbrack$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.