The total radiant energy per unit area, normal to the direction of incidence

The Total Radiant Energy Per Unit Area Normal To The Physics Question

The total radiant energy per unit area, normal to the direction of incidence, received at a distance R from the centre of a star of radius r, whose outer surface radiates as a black body at a temperature T K is given by: (where σ is Stefan’s constant)


(a) σr²T⁴ / R²
(b) σr²T⁴ / 4πr²
(c) σr⁴T⁴ / r⁴
(d) 4π σr²T⁴ / R²

Correct Answer:

σr²T⁴ / R²


E = S / S₀ σT⁴ = 4πr² / 4πR² σT⁴
σr²T⁴ / R²

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Topics: Properties of Bulk Matter (130)
Subject: Physics (2479)

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