A copper disc of radius 10 cm placed with its plane normal to a uniform magneic field completes 1,200 rotations per minute. If induced e.m.f. between the centre and edge of the disc in 6.284 m V, find the intensity of the magnetic field Take `pi = 3.142`

The radius of a coil s changing at the rate of 10^-2 units in a normal magnetic field of 10^-3 units and the induced e.m.f. is 1muV . Find the final radius of the coil.

A circular coil of 20 turns and radius 10 cm is placed in a uniform magnetic field of 0.10 T normal to the plane of the coil. If the current in the coil is 5.0 A, what is the average force on each electron in the coil due to the magnetic field? (The coil is made of copper wire of cross-sectional area 10^-5 m^2 , and the free electron density in copper is given to be about 10^29 m^-3 .)

A metal disc of radius 200 cm is rotated at a constant angular speed of 60 rad s^-1 in a plane at right angles to an external field of magnetic induction 0.05 Wb m^-1 . Find the e.m.f. induced between the centre and a point on the rim.

A circular copper disc 10 cm in radius rotates at 20pi rad/s about an axis through its centre and perpendicular to the disc. A uniform magnetic field of 0.2 T acts perpendicular to the disc. What is the induced current if the resistance of the disc is 2Omega ?

A metal rod of length 1 m is rotated about one of its ends in a plane at right angles to a uniform magneic field of 2.5 xx 10^-3 Wb m^-2 . If its makes 30 r.p.s. Calculate the induced e.m.f. between its ends.

A rectangular conductor LMNO is placed in a uniform magnetic field vecB directed perpendicular to the plane of conductor . Obtain an expression for the e.m.f. induced in the arm MN, when the arm is moved toward the left with a speed v.