Question
A black body is at a temperature of 5760 K. The energy of radiation emitted by the body at wavelength 250 nm is U1, at wavelength 500 nm is U2 and that at 1000 nm is U3. Wien's constant, b = 2.88 x 106 nmK. Which of the following is correct?
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U3 = 0
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U1 > U2
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U2 > U1
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U1 = 0
Solution
C.
U2 > U1
Given, temperature, T1 = 5760 K
Given that energy of radiation emitted by the body at wavelength 250 nm in U1, at wavelength 500 nm is U2 and that at 1000 nm is U3.
Now, according to Wein's law, we get
where, b = Wien's constant = 2.88 x 106 nmK
is the wavelength corresponding to maximum energy, so U2 > U1.
