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A surface at temperature T(0)K receives ...

A surface at temperature `T_(0)K` receives power `P` by radiation from a small sphere at temperature `T ltT_(0)` and at a distance d. If both `T` and d are doubled the power received by the surface will become .

A

`8P`

B

`4P`

C

`2P`

D

`P`

Text Solution

Verified by Experts

The correct Answer is:
B
`(Power)/(Area)` = Intensity
Power absorbed by the foil = Intensity at foil xx Area of foil
`implies P = (P_(a))/(4pid^(2)) xx A = ((sigmaA_(theta) T^(4))/(4pid^(2)))A`
Now `P'= (sigmaA_(theta)(2T)^(4) xx A)/(4pi(2d)^(2)) = 4P`
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