A wheel of radius 10 cm can rotate freely about its centre as shown in fig.A string is wrapped over its rim and is pulled by a force of 5.0N .It is found that the torque prodces an angular acceleration 2.0 rad//s in the wheel.calculate the moment of inertia of the wheel.

A flywheel of mass 30 kg has a radius of 0.2 m .What force should be applied tangentially to the rim of the flywheel so that it acquires an angular acceleration of 23 rad//s^2 ?

A wheel rotates with a constant acceleration of 2.0 rad//s^2 .If the wheel starts from rest,how many revolutions will it make in the first 10 seconds?

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. Calculate the potential difference developed between the axis of the disc and the rim.

A solid metal sphere of radius r has charge +Q. The sphere has radius 36 cm This charge is one the surface of the sphere but it may be considered to be a point charge at its centre. A spark suddenly connects the metal sphere in to the earth, causing the potnetial of the sphere to be reduced from 7.0 xx 10^5V to 2.5 xx 10^5V . Calculate the energy dissipated in the spark.

A string is wrapped around the rim of a wheel of moment of inertia 0.20 kg m^2 and radius 20 cm.the wheel is free to rotate about its axis .Initially,the wheel is at rest.The string is now pulled by a force of 20 N.Find the angular velocity of the wheel after 5.0 seconds.

A circular coil of 16 turns and radius 10 cm carrying a current of 0.75 A rests with its plane normal to an external field of magnitude 5.0 xx 10^-2 T. The coil is free to turn about an axis in its plane perpendicular to the field direction. When the coil is turned slightly and released, it oscillates about its stable equilibrium with a frequency of 2.0 s^-1 . What is the moment of inertia of the coil about its axis of rotation?

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 wheel with 8 matallic spokes each 50 cm long is rotated with a speed of 120 rev//mi n in a plane normal to horizontal component of earth's magnetic field. Earth's magnetic field at the phase is 0.4 G and angle of dip 60^(@) . Calculate the emf induced between the axle and rim of the wheel. How is the emf affected if number of spokes is increased ?

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 small retangular coil ABCD contains 140 turns of wire. The sides AB and BC of the coil are of length 4.5 and 2.8 cm respectively, as shown in the figure The coil is held between the poles of a large magnet so that the coil can rotate about an axis thorugh its centre. The magnet produces a uniform magnetic field of flux density B between its poles. When the current in the coil is 170 mA, the maximum torque produced in the coil is 2.1 xx 10^-3 N m . For the coil in the position shown in the figure. calculate the magnitude of the force on (i) side AB of the coil and (ii) side BC of the coil.