Electromagnetic...

A copper disc of radius 0.1 m is rotated about its centre with 20 rev/s in an uniform magnetic field of 0.1 T with its plane perpendicular to the field. The emf induced across the radius of the disc is

A circular coil of radius R = 10 cm having 500 turns and total resistance 2 Ω is placed initially perpendicular to the earth's magnetic field of 3 × 10^-5 T. The coil is rotated about its vertical diameter by an angle 2π in 0.5 . The induced current in the coil is

A boat is moving due East in a region where the earth's magnetic field is 5.0 × 10^-5 NA^-1 m^-1 due North and horizontal. The boat carries a vertical aerial 2 m long. If the speed of the boat is 1.50 ms^-1 , the magnitude of the induced emf in the wire of aerial is

A horizontal straight wire 20 m long extending from East to West is falling with a speed of 5.0 ms^-1 , at right angles to the horizontal component of the earth's magnetic field 0.030 ×10^-4 Wbm^-2 . The instantaneous value of the emf induced in the wire will be

Electric fields induced by changing magnetic fields are

A square loop of wire, side length 10 cm is placed at angle of 45° with a magnetic field that changes uniformly from 0.1 T to zero in 0.7 s. The induced current in the loop (its resistance is 1 Ω ) is

A 50 turns circular coil has a radius of 3 cm, it is kept in a magnetic field acting normal to the area of the coil. The magnetic field B increased from 0.10 T to 0.35 T in 2 ms. The average induced emf in the coil is

A current passing through a coil of self inductance of 2 mH changes at the rate of 20 mAs^-1 . The emf induced in the coil is

An inductor having coefficient of self induction 40 mH. What is the energy stored in it, when a current of 2 A is passed through it ?

Magnetic flux linked with a coil is ϕ = 5t² + 2 t + 3, where t is in sec and ϕ is in weber. At time t =1 s, the value of induced emf in volt.