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MHT CET 2026 (11 Apr, Shift 1) · Thermal Radiation: Black Body, Stefan & Wien

Thermal Radiation: Black Body, Stefan & Wien question from MHT CET 2026 (11 Apr, Shift 1)

Q37MHT CET 2026 · 11 APR · SHIFT 1Medium

Thermal Radiation: Black Body, Stefan & Wien

The energy spectrum of a black body exhibits a maximum of wavelength λ0\lambda_0. The temperature of the black body is now changed such that the energy is maximum at wavelength 3λ02\frac{3\lambda_0}{2}. The ratio of power radiated by the black body will be

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Answer: (b)

  1. Wien: T∝1λmT \propto \frac{1}{\lambda_m}, so T′T=λ03λ0/2=23\frac{T'}{T} = \frac{\lambda_0}{3\lambda_0/2} = \frac{2}{3}.
  2. Stefan: P′P=(23)4=1681\frac{P'}{P} = \left(\frac{2}{3}\right)^4 = \frac{16}{81}
  3. So the answer is (b) 1681\frac{16}{81}.
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