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

A rectangular coil of 100 turns, having dimensions 25 cm 20 cm , is rotated in a uniform magnetic field of 0.2 T . The electrical resistance of the coil is 20 . If the maximum induced current in the coil is 3.14 A , what is the frequency of rotation of the coil in revolutions per minute (rpm)? (Take = 3.14 )

Options

  1. A600 rpm
  2. B10 rpm
  3. C300 rpm
  4. D1200 rpm

Correct answer

A. 600 rpm

Step-by-step solution

The area of the rectangular coil is A = 25 cm 20 cm = 0.25 m 0.20 m = 0.05 m ^2 . The maximum induced EMF in a rotating coil is given by _ max = NAB , where = 2 f . The maximum induced current is I_ max = _ max R = NAB(2 f) R . Substituting the given values: 3.14 = 100 0.05 0.2 2 3.14 f 20 3.14 = 1 6.28 f 20 f = 3.14 20 6.28 = 10 Hz . To convert the frequency to revolutions per minute (rpm), multiply by 60 : Frequency in rpm = 10 60 = 600 rpm . Answer: 600 rpm

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