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MHT CET202121 Sep 2021Morning ShiftPhysicsThermal Properties of MatterActual

A black rectangular surface of area ' a ' emits energy ' E ' per second at 27^ C . If length and breadth is reduced to ( 1 3 )^ rd of initial value and temperature is raised to 327^ C then energy emitted per second becomes

Options

  1. A16 E 9
  2. B8 E 9
  3. C4 E 9
  4. DE 9

Correct answer

A. 16 E 9

Step-by-step solution

E = e AT ^4 and A = b E^ E = A^ (327+273)^4 A(27+273)^4 E^ E = 1 9 ( 600 300 )^4 aligned & E ^ = 1 9 (2)^4 E & E ^ = 16 E 9 aligned

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