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JEE Main201815 Apr 2018Evening ShiftPhysicsElectromagnetic InductionActual

At the centre of a fixed large circular coil of radius R , a much smaller circular coil of radius r is placed. The two coils are concentric and are in the same plane. The larger coil carries a current I. The smaller coil is set to rotate with a constant angular velocity about an axis along their common diameter. Calculate the emf induced in the smaller coil after a time t of its start of rotation.

Options

  1. A₀ I 2 R r ^2 t
  2. B₀ I 4 R r^2 t
  3. C₀ I 2 R r^2 t
  4. D₀ I 4 R r ^2 t

Correct answer

C. ₀ I 2 R r^2 t

Step-by-step solution

According to Faraday's law of electromagnetic induction, array r e=- d d t and =B A t=B r^2 t e=- d d t ( r^2 B t )= r^2 B t( ) e= ₀ I 2 R r^2 t ( B= ₀ I 2 R ) array

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