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BITSAT2015PhysicsElectromagnetic InductionActual

A conducting square loop is placed in a magnetic field B with its plane perpendicular to the field. The sides of the loop start shrinking at a constant rate . The induced emf in the loop at an instant when its side is ' a ' is

Options

  1. A2 a B
  2. Ba² B
  3. C2 a² B
  4. Da B

Correct answer

A. 2 a B

Step-by-step solution

At any time t , the side of the square a= (a₀ .- t), where a₀= side at t=0 At this instant, flux through the square : array l =B A 0^ =B (a₀- t )² emf induced E=- d d t E=-B .2 (a₀- t )(0- )=+2 a B array

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