Two identical circular wires P and Q each of radius R and carrying current 'I' are kept in perpendicular planes such that they have a common centre as shown in the figure. Find the magnitude and direction of the net magnetic field at the common centre of the two coils.

A hexagonal loop of a metallic wire is of each side a and carries a current I . Find the magnitude of magnetic field at the centre of the loop.

The plane of a circular coil is horizontal. It has 10 turns each of radius 8cm. A current of 2 A flows through it. The current appears to flow clockwise from a point above the coil. Find the magnitude and direction of magnetic field at the centre of the coil due to the current.

A circular coil of 50 turns and radius 0.2 cm carries a current of 12 A. Find magnetic field at the centre of the coil.

A point charge q is moving with speed v perpendicular to magnetic field B as shown in figure. Explain what should be the magnitude and direction of the applied electric filed so that the net force acting on the charge is zero.

A wire loop is formed by joining two semicircular wires of radii r_1 and r_2 as shown in the figure . The loop carries a current I, find the magnetic field at the centre O.

Two similar coils each of radius R and no. of turns N are lying concentrically with their planes at right angle to each other. The currents following in them are 1 A and sqrt3A respectively. What is the magnetic field at centre of the coils ?

A rectangular loop of metallic wire is of length a and breadth b and carries a current I . Find the magnitude of magnetic field at the centre O of the loop.

On what factors does the magnitude of magnitude of magnetic field at the centre of a current carrying circular wire depends.