Two cylindrical hollow drums of radii and 2R, and of a common height h, are rotating with angular velocities `omega` (anticlockwise) and `omega` (clockwise), respectively, Their axes, fixed are parallel and in a horizontal plane separated by `(3R + delta)`. They are now brought in contact `(deltararr 0)`. What would be the ratio of final angular velocities when fiction ceases?

Two cylindrical hollow drums of radii and 2R, and of a common height h, are rotating with angular velocities omega (anticlockwise) and omega (clockwise), respectively, Their axes, fixed are parallel and in a horizontal plane separated by (3R + delta) . They are now brought in contact (deltararr 0) . Show the frictional forces just after contact.

Two cylindrical hollow drums of radii and 2R, and of a common height h, are rotating with angular velocities omega (anticlockwise) and omega (clockwise), respectively, Their axes, fixed are parallel and in a horizontal plane separated by (3R + delta) . They are now brought in contact (deltararr 0) . Identify forces and torques external to the system just after contact.

A disc of radius R is rotating with an angular speed omega_0 about a horizontal axis. it is placed on a horizontal table. The coefficient of kinetic friction is mu_k . What was the velocity of its centre of mass before being brought in contact with the table?

Two parallel vertical metallic rails AB and CD are separated by 1m. They are connected at the two ends by resistances R_1 and R_2 as shown in the figure. A horizontal metallic bar 1 of mass 0.2 kg slides without friction, vertically down the rails under the action of gravity. There is a uniform horizontal magnetic field of 0.6 T perpendicular to the plane of the rails. It is observed that when the terminal velocity is attained, the powers dissipated in R_1 and R_2 are 0.76W and 1.2W respectively (g=9.8m//s^2) The value of R_2 is

A magnetic field vecB is confined to a region r le a and points out of the paper (the z axis), r = 0 being the centre of the circular region. A charged ring (charge = Q) of radius b, b>a and mass m lies in the x-y plane with its centre at the origin. The ring is free to rotate and is at rest. the magnetic field is brought to zero in time Deltat . Find the angular velocity omega of the ring after the field vanishes.

A disc of radius R is rotating with an angular speed omega_0 about a horizontal axis. it is placed on a horizontal table. The coefficient of kinetic friction is mu_k . Which force is responsible for the effects in what happens to the linear velocity of a point on its rim when placed in contact with the table? and What happens to the linear speed of the centre of mass when disc is placed in contact with the table?

An a.c. generator consists of a coil of 50 turns and area 2.5 m^(2) rotating att an angular speed of 60 rad s^(-1) in a uniform magnetic field B = 0.3 T between two fixed pole pieces. The resistance of the circuit including that of coil is 500 Omega . Find What will be the orientaiton of the coil w.r.t. the magnetic field to have (a) maximum (b) zero magnetic flux ?

A magnetic filed vecB=B_0 sin"(omega t)hatk covers a large region where a wire AB slides smoothly over two parallel conductors separated by a distance d (Fig. EP 6.22). The wires are in the x-y plane. The wire AB (of length d) has resistance R and parallel wires have negligible resistance. If AB is moving with velocity v, what is the current in the circuit? what is the force needed to keep the wire moving at constant velocity?