Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEETPhysicsElectromagnetic Induction

A circular coil of 50 turns and cross-sectional area 2 m ^2 is placed such that its plane is perpendicular to a time-varying magnetic field. The magnetic field changes with time according to the relation B(t) = 0.2t^2 - 0.05t (where B is in tesla and t is in seconds). The magnitude of the induced emf in the coil at t = 2 s will be:

Options

  1. A0.75 V
  2. B70 V
  3. C75 V
  4. D0 V

Correct answer

C. 75 V

Step-by-step solution

The magnetic flux linked with the coil is given by = NBA . Since the plane of the coil is perpendicular to the magnetic field, the angle between the area vector and the magnetic field is = 0^ . Thus, (0^ ) = 1 . Substituting the given values: (t) = 50 2 (0.2t^2 - 0.05t) (t) = 100(0.2t^2 - 0.05t) = 20t^2 - 5t According to Faraday's law, the magnitude of the induced emf is |e| = d dt . Differentiating the flux equation with respect to time: |e| = d dt (20t^2 - 5t) = 40t - 5 At t = 2 s , the magnitude of the induced e

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 2026Semicircular 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 t 2026 Full Electromagnetic Induction list All NEET PYQs