Question
Assuming the sun to have a spherical outer surface of radius r, radiating like a black body at a temperature to C, the power received by a unit surface (normal to the incident rays) at a distance R from the centre of the sun is :
Solution
D.
From Stefan's law, the rate at which energy is radiated by sun at its surface si
P = σ x 4 πr2T4
[Sun is a perfectly black body as it emits radiations of all wavelengths and so for it e =1]
The intensity of this power at earth's surface (under the assumption R >>ro) is
The intensity of this power at earth's surface (under the assumption R >>ro) is
