In the given figure magnetic field at the center of ring `(O)` is `8sqrt(2)T` . Now it is turned through a `90^(@)` about xx` axis,so that two semicircular parts are mutually perpendicular.Find the value of magnetic field (in tesla) at centre

Find the experssion for the magnetic field at the centre O of a coil bent in the form of a square of side 2a , carrying current I, figure.

A supereconducting round ring of radius a and inductance L was located in a uniform in a uniform magnetic field of induction B . The ring plane was parallel to the vector B and the current in the ring was equal to zero, then the ring was turned through 90^(@) so that its plane became perpendicular to the field. Find (a) the current induced in the ring after the turn (b) the work performed during the turn.

A current I, flowing in a long and straight wire along z-axis, is directed into two identical semicircular portions lying in y-z and x-z planes as shown in the figure. The magnetic field at the centre O is

A wire loop formed by joining two semicircular wires of radii R_1 and R_2 carries a current I as shown in figure. Find the magnetic field induction at the centre O.

A rectangular loop of length l and breadth b is situated in a uniform magnetic field of induction B with its plane perpendicular to the field as shown in the figure . Calculate the rate of change of magnetic flux and the induced emf if the loop is rotated with constant angular velocity omega (a) about an axis passing through the centre and perpendicular to the loop. (b) about an axis passing through the centre parallel to the breadth through angle 180^(@) .

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 closely wound, circular coil with radius 2.40 cm has 800 turns. (a) What must the current in the coil be if the magnetic field at the centre of the coil is 0.0580 T ? (b) At what distance x from the centre of the coil, on the axis of the coil, is the magnetic field half its value at the centre?