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The rate of emission of heat energy per ...

The rate of emission of heat energy per unit area of an iron ball of radius 10 cm is `10J//m^2s` s, then rate ·of emission of heat energy per unit area by a copper ball of radius 5 cm at same temperature will be ( emissivity of both the balls is same)

A

`2J/s`

B

`2.5J/s`

C

`2cals`

D

none of these

Text Solution

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The correct Answer is:
B
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