A spherical black body with a radius of 12 cm radiates 450 watt power at 500 K . If the radius were halved and the temperature doubled, the power radi - Physics MCQ NEET 2017 2026 | ExamTest.live

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A spherical black body with a radius of 12 cm radiates 450 watt power at 500 K . If the radius were halved and the temperature doubled, the power radiated in watt would be:

Solution & Step-by-step Explanation

According to Stefan-Boltzmann Law, P = σ e A T^{4} \propto r^{2} T^{4} . \frac{P _{2}}{P _{1}} = (\frac{r _{2}}{r _{1}})^{2} (\frac{T _{2}}{T _{1}})^{4} . \frac{P _{2}}{450} = (\frac{1}{2})^{2} (2)^{4} = \frac{1}{4} \times 16 = 4 . P_{2} = 450 \times 4 = 1800 watt .

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A spherical black body with a radius of 12 cm radiates 450 watt power at 500 K . If the radius were halved and the temperature doubled, the power radiated in watt would be:

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