A stiff semi-circular wire of radius R is rotated in a uniform magnetic field B about an axis passing through its ends. If the frequency of rotation of wire be f, calculate the amplitude of alternating emf induced in the wire.

A metallic wire coil is stationary in a uniform magnetic field. What is the e.m.f .induced in the coil?

A current i flows in a circular coil of radius r . If the coil is placed in a uniform magnetic field B with its plane parallel to the field, magnitude of the torque that acts on the coil is

Radius of gyration of disc rotating about an axis perpendicular to its plane passing through its centre is (If R is the radius of disc)

A thinuniform circular disc of mass M and radius R is rotating in a horizontal plane about an axis passing through its centre and perpendicular to its plane withan angular velocity omega .Another disc of same dimensions but of mass M/4 is placed gently onthe first disc co-axially, then the angular velocity of the system is

A coil of 100 turns each of area 0.1 m^2 is rotated at constant speed of 300 r.p.m. in a uniform magnetic field of induction 0.02 Wb//m^2 about an axis in the plane of the coil and perpendicular to the direction of the coil.Calculate the maximum value of induced e.m.f.

A coil of 100 turns each of area 0.12m^2 is rotated with constant speed 62.8rad/s in uniform magnetic field of induction 0.02 tesla about an axis in the plane of coil and perpendicular to the direction of field. Calculate maximum value of induced e.m..f.in the coil.

If a solid sphere of mass 1kg and radius 3 cm is rotating about an axis passing through its centre with an angular velocity of 50 rad/s, then the kinetic energy of rotation will be

A coil of 50 turns each of area 0.12m^2 is rotated at constant speed of 600 r.p.m. in uniform magnetic field of induction 0.02 tesla about an axis in the plane of coil and perpendicular to direction of field.Calculate maximum e.m.f. induced in the coil.

A circular disc of radius R and thickness R/6 has moment of inertia I about an axis passing through. Its is melted and recast into a solid sphere. What is the moment of inertia of the solid sphere about its diameter as the axis of rotation?

A coil of 2000 turns and of mean radius 5 cm, makes 300 revolutions per minute around one of its diameters in a uniform magnetic field of induction 2.5 xx 10^-5 Wb/m^2 at right angles to its axis of rotation .Calculate the maximum e.m.f. induced in the coil and also its r.m.s. value.