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MHT CET202313 May 2023Evening ShiftPhysicsElectromagnetic InductionActual

A metal disc of radius : 'R' rorates with an angular velocity ' ' 'about an axis perpendicular to its plane passing through its centre in a magnetic' field of induction ' B ' acting perpendicular to the plane of the disc. The magnitude of induced. e.m.f. between the rim and axis of the disc is

Options

  1. ABR ^2
  2. B2 ^2 BR ^2
  3. CBR ^2
  4. DBR ^2 2

Correct answer

D. BR ^2 2

Step-by-step solution

Induced e.m.f., e = - d dt =- d ( BA ) dt =- B dA dt .( B = constant ) Area swept between axis and the rim, dA = R ^2 Time during which the change in flux taking place, dt = 2 e = - B R ^2 2 / = - B R ^2 2 | e |= B R ^2 2

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