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JEE Main20202 Sep 2020Evening ShiftPhysicsUnits and DimensionsActual

If momentum ( P ) , area ( A ) and time ( T ) are taken to be the fundamental quantities then the dimensional formula for energy is :

Options

  1. AP 2   AT - 2
  2. BPA - 1   T - 1
  3. CPA 1 / 2 T - 1
  4. DP 1 / 2 AT - 1

Correct answer

C. PA 1 / 2 T - 1

Step-by-step solution

Let dimension formula of energy will be E = A a T b P c P = M 1 L 1 T - 1 A = L 2 T = T 1 M 1 L 2 T - 2 = M C L 2 a + c T b - c by comparison C = 1 . . . . . . . . . 1 2 a + c = 2 . . . . . . 2 b - c = - 2 . . . . . . . . 3 c = 1 ,    a = 1 / 2 , b = - 1 E = A 1 / 2 T - 1 P 1

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