Question

If the intensity of radiation emitted by a surface covered with lamp black (α = 0.96) in the normal direction is 1.85 x 103

W/m2

Sr. Calculate the temperature of the surface if it follows Lambert’s Cosine Law

Answer 1

Lambert’s cosine law states that the radiant intensity from the ideal diffusely reflecting surface and cosine of the angle θ between the direction of incident light and surface normal are directly proportional.

Heat radiated per second:

$E= \sigma AT^4$

$1.85\times10^3= 5.7\times10^-8 \times 1\times T^4$

$T =424.44 ^0K$