Question

A black body is at a temperature of 2880 K. The energy of radiation emitted by this body between wave lengths 499 nm and 500 nm is $U_1$, between 999 nm and 1000 nm is $U_2$ and between 1499 nm and 1500 nm is $U_3$. The Wien’s constant b = 2.88 $\times$ 106 nm K. Then

• A.
• B.
• C. >
• D. >

Answer 1

The correct option is D

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Form Wien’s displacement law ${\lambda }_{m}T=b$, the maximum radiation is emitted at wavelength

${\lambda }_m=\frac{b}{T}=\frac{2.88\times {10}^{6}nmk}{2880K}=1000nm$

Hence $U_2$ is the maximum. Since a black body emits radiation at all wavelengths $U_1\ne 0and{U}_3\ne 0$. Hence the correct choice is (d).