Question

The plots of intensity versus wavelength for three black bodies at temperatures $T_1, T_2$ and $T_3$ respectively are as shown. Their temperature are such that

• A. $T _{1}> T _{2}> T _{3}$
• B. $T _{1}> T _{3}> T _{2}$
• C. $T _{2}> T _{3}> T _{1}$
• D. $T _{3}> T _{2}> T _{1}$

Answer 1

Answer: (B)

According to Wien’s law,
$\lambda_{m} \propto \frac{1}{T}$
From the graph $\left(\lambda_{m}\right)_{1}<\left(\lambda_{m}\right)_{3}<\left(\lambda_{m}\right)_{2}$
Therefore $T_{1}>T_{3}>T_{2}.$