A ring of mass m, radius r having charge q uniformly distributed over it and free to rotate about its own axis is placed in a region having a magnetic field B parallel to its axis. If the magnetic field is suddenly switched off, the angular velocity acquired by the ring is:

A thin non-conducting ring of mass m carrying a charge q can freely rotate about its axis. At t = 0 , the ring was at rest and no magnetic field was present. Then suddenly a magnetic field B was set perpendicular to the plane. Find the angular velocity acquired by the ring.

A thin non-conducting ring of mass m carrying a charge q can freely rotate about its axis. At t = 0 , the ring was at rest and no magnetic field was present. Then suddenly a magnetic field B was set perpendicular to the plane. Find the angular velocity acquired by the ring.

A non-conducting ring of mass m and radius R has a charge Q uniformly distributed over its circumference. The ring is placed on a rough horizontal surface such that plane of the ring is parallel to the surface. A vertical magnetic field B = B_0t^2 tesla is switched on. After 2 a from switching on the magnetic field the ring is just about to rotate about vertical axis through its centre. (a) Find friction coefficient mu between the ring and the surface. (b) If magnetic field is switched off after 4 s , then find the angle rotated by the ring before coming to stop after switching off the magnetic field.

A non-conducting ring of mass m and radius R has a charge Q uniformly distributed over its circumference. The ring is placed on a rough horizontal surface such that plane of the ring is parallel to the surface. A vertical magnetic field B = B_0t^2 tesla is switched on. After 2 a from switching on the magnetic field the ring is just about to rotate about vertical axis through its centre. (a) Find friction coefficient mu between the ring and the surface. (b) If magnetic field is switched off after 4 s , then find the angle rotated by the ring before coming to stop after switching off the magnetic field.

A ring of mass m and radius R is given a charge q. It is then rotated about its axis with angular velocity omega .Find (ii) Magnetic field produced at the centre of ring.

A ring of mass m and radius R is given a charge q. It is then rotated about its axis with angular velocity omega .Find (ii) Magnetic field produced at the centre of ring.

A non - conducting ring of mass m = 4 kg and radius R = 10 cm has charge Q = 2 C uniformly distributed over its circumference. The ring is placed on a rough horizontal surface such that the plane of the ring is parallel to the surface. A vertical magnetic field B=4t^(3)T is switched on at t = 0. At t = 5 s ring starts to rotate about the vertical axis through the centre. The coefficient of friction between the ring and the surface is found to be (k)/(24) . Then the value of k is

A non - conducting ring of mass m = 4 kg and radius R = 10 cm has charge Q = 2 C uniformly distributed over its circumference. The ring is placed on a rough horizontal surface such that the plane of the ring is parallel to the surface. A vertical magnetic field B=4t^(3)T is switched on at t = 0. At t = 5 s ring starts to rotate about the vertical axis through the centre. The coefficient of friction between the ring and the surface is found to be (k)/(24) . Then the value of k is

A thin non conducting ring of mass m , radius a carrying a charge q can rotate freely about its own axis which is vertical. At the initial moment, the ring was at rest in horizontal position and no magnetic field was present. At instant t=0 , a uniform magnetic field is switched on which is vertically downward and increases with time according to the law B=B_0t . Neglecting magnetism induced due to rotational motion of ring. Angular acceleration of ring is

A thin non conducting ring of mass m , radius a carrying a charge q can rotate freely about its own axis which is vertical. At the initial moment, the ring was at rest in horizontal position and no magnetic field was present. At instant t=0 , a uniform magnetic field is switched on which is vertically downward and increases with time according to the law B=B_0t . Neglecting magnetism induced due to rotational motion of ring. Angular acceleration of ring is