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A sphere of radius 50 cm is maintained a...

A sphere of radius 50 cm is maintained at a constant temperature, radiates energy at the rate of 0.5 kcal/s. then the emissive power of sphere is (`J=4.2xx10^(3)J//kcal`)

A

`11.11xx10^(-4)J//m^(2)s`

B

`6xx10^(2)J//m^(2)s`

C

`11.11xx10^(-2)J//m^(2)s`

D

`11.11J//m^(2)s`

Text Solution

Verified by Experts

The correct Answer is:
D
`E=(Q)/(At)=(0.5xx4.2xx10^(-3))/(4pixx0.5xx0.5xx60)=11.11`
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