Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
MHT CET Medical202624 April 2026Morning ShiftPhysicsElectromagnetic InductionActual

Semicircular wire of radius R is rotated in a uniform magnetic field about an axis passing through its ends. If the frequency of rotation is f, the amplitude of induced e.m.f. in the wire is [B = magnetic field induction]

Options

  1. A²RfB
  2. B²R²fB
  3. C2 ²RfB
  4. D2 ²Rf²B

Correct answer

B. ²R²fB

Step-by-step solution

The area of the semicircular region is A = 1 2 R^2 . We can consider a closed loop formed by the semicircular wire and the straight segment joining its ends. Since this straight segment lies on the axis of rotation, its velocity is zero, and no motional emf is induced in it. Therefore, the emf induced in the semicircular wire is equal to the emf induced in the entire closed loop. Assuming the magnetic field is perpendicular to the axis of rotation for maximum induced emf, the magnetic flux through the loop at any i

Practice Electromagnetic Induction on Quantrex Academy →

More from Electromagnetic Induction

A square loop of area A is moving out of the uniform magnetic field (B) with constant velocity v . The EMF (e) induced in the loop is 2026The value of mutual inductance of two coils is 6 mH. The current in one of the coil changes from 7 A to 2 A in 0.2 second, so that e.m.f. is induced in the other coil. If the resis 2026Two identical inductors are connected in parallel. If the parallel combination stores 40 J of magnetic field energy when a total current of 2 A is passed through it, the value of t 2026Two coils have mutual inductance of 0.004 H . The current changes in the first coil according to the relation i = i₀ t , where i₀ = 6 A and = 100 rad/s . The maximum value of emf i 2026The coefficient of coupling is 0.8 . If the mutual inductance is 8 H , then the values of self-inductances L₁ and L₂ of the coil are 2026The self inductance L of a solenoid of length l and area of cross-section A, with a fixed number of turns N increases as 2026A wire of length 1 m is moving at a speed of 2 m/s perpendicular to its length in a homogeneous magnetic field of 0.5 T . If the ends of the wire are joined to a circuit of resista 2026A wire of length l in the form of a square loop is in a plane normal to magnetic field B. If the length of the wire is decreasing at the rate dl dt , the e.m.f. induced is e₁ . If 2026 Full Electromagnetic Induction list All MHT CET Medical PYQs