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MHT CET 2025 (21 Apr, Shift 1) · Thermal Radiation: Black Body, Stefan & Wien

Thermal Radiation: Black Body, Stefan & Wien question from MHT CET 2025 (21 Apr, Shift 1)

Q56MHT CET 2025 · 21 APR · SHIFT 1Medium

Thermal Radiation: Black Body, Stefan & Wien

A rectangular block of surface area A emits energy E per second at $27^\circ\text{C}$ . If length and breadth is reduced to half of initial value and temperature is raised to $327^\circ\text{C}$ then energy emitted per second becomes

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Answer: (b)

$E \propto A T^4$ .
Length and breadth halved: $A \to \frac{A}{4}$ .
$T: 300\text{ K} \to 600\text{ K}$ , factor $16$ .
$E' = \frac{16}{4}E = 4E$ , so the answer is (b).

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