A conducting ring having mass kg, radius and resistance is placed on a frictionless horizontal surface. A time varying magnetic field is present in the region, where t is time in seconds and is vertical. (Take ). Then choose the correct option(s).

force ‘F’ is applied at the top of a ring of mass ‘M’ and radius ‘R’ placed on a rough horizontal surface as shown in the figure. Friction is sufficient to prevent slipping. The friction force acting on the ring is

A conducting loop of radius 10π√cm is placed perpendicular to a uniform magnetic field of 0.5T. The magnetic field is decreased to zero in 0.5s at a steady rate. The induced emf in the circular loop at 0.25s is:

A metallic rod of 1 m length is rotated with a frequency of 50 revolution per second, with one end hinged at the centre and the other end at the circumference of a circular metallic ring of radius 1 m about an axis passing through the centre and perpendicular to the plane of the ring. A constant uniform magnetic field of 1 T parallel to the axis is present everywhere. The emf between the centre and the metallic ring is:

A circular coil of radius R carries an electric current. The magnetic field due to the coil at a point on the axis of the coil located at a distance r from the centre of the coil, such that r >> R, varies :-

A conducting circular loop is placed in a uniform magnetic field, B=0.025 TB=0.025 T with its plane perpendicular to the direction of the magnetic field. The radius of the loop is made to shrink at a constant rate of 1 mm s−11 mm s-1. Find the emf induced in the loop when it's radius is 2 cm2 cm.