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MHT CET 2026 (14 May, Shift 2) · Thermal Radiation: Black Body, Stefan & Wien

Thermal Radiation: Black Body, Stefan & Wien question from MHT CET 2026 (14 May, Shift 2)

Q32MHT CET 2026 · 14 MAY · SHIFT 2Medium

Thermal Radiation: Black Body, Stefan & Wien

The power radiated by a black body is P and it radiates maximum energy at wavelength λ0\lambda_0. If the temperature of the black body is now changed so that it radiates maximum energy at wavelength 3λ04\frac{3\lambda_0}{4}, the power radiated by it becomes nP. The value of n is

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Answer: (a)

  1. Wien: T∝1λmT \propto \frac{1}{\lambda_m}, so T′T=43\frac{T'}{T} = \frac{4}{3}.
  2. Stefan: P∝T4⇒n=(43)4=25681P \propto T^4 \Rightarrow n = \left(\frac{4}{3}\right)^4 = \frac{256}{81}
  3. So the answer is (a) 25681\frac{256}{81}.
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