InterviewSolution
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InterviewSolution
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The rectangular surface of area `8 cm xx 4 cm` of a black body at temperature `127^(@)C` emits energy `E` per section if length and breadth are reduced to half of the initial value and the temperature is raised to `327^(@)C`, the ratio of emission of energy becomesA. `(3)/(8)E`B. `(81)/(16)E`C. `(9)/(16)E`D. `(81)/(64)E` |
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Answer» Correct Answer - D Energy radiated by body per second `(Q)/(t)Asigma T^4` or `(Q)/(t)proplxxbxxT^4` (Area `= l xx b`) `:. (E_2)/(E_1)=(l_2)/(l_1)xx(b_2)/(b_1)xx((T_2)/(T_1))^4=((l_(1)//2))/(l_(1))xx((b_(1)//2))/(b_(1))xx((600)/(400))^4` `=(1)/(2)xx(1)/(2)xx((3)/(2))^4impliesE_2=(81)/(64)E` |
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