Five long wires A, B, C, D and E, each carrying current I are arranged to form edges of a pentagonal prism as shown in Fig. EP 4.29. Each carries current out of the plane of paper.
What will be magnetic induction at a point on the axis O? Axis is at a distance R from each wire.

A long straight wire carries a current of 35 A. What is the magnitude of the field B at a point 20 cm from the wire?

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.

Two long straight parallel wieres are 2m apart, perpendicular to the plane of the paper. The wire A carries a current of 9.6 A, directed into the plane of the paper. The wire B carries a current such that the magnetic field of induction at the point P, at a distance of 10/11 m from the wire B, is zero. find the magnitude of the magnetic field of induction of the pont S.

Two long straight parallel wieres are 2m apart, perpendicular to the plane of the paper. The wire A carries a current of 9.6 A, directed into the plane of the paper. The wire B carries a current such that the magnetic field of induction at the point P, at a distance of 10/11 m from the wire B, is zero. find the magnitude and directiion of the current in B.

A metal bar AB can slide on two parallel thick metallic rails separated by a distance l. A resistance R and an inductance L are connected to the rails as shown in the figure. A long straight wire carrying a constant current I_(0) is placed in the plane of the rails and perpendicular to them as shown. The bar AB is held at rest at a distance x_(0) from the long wire. At t=0, it is made to slide on the rails away from wire. Answer the following questions. Find a relation among i, (di)/(dt) and (d phi)/(dt) , where i is the current in the circuit and phi is the flux of the megnetic field due to the long wire through the circuit.

The magnetic field B due to a current carrying circular loop of radius 12cm at its centre is 0.5xx10^-4T . Find the magnetic field due to this loop at a point on the axis at a distance of 5.0cm from the centre.

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.

A long straight wire carrying current of 25 A rests on a table as shown in Fig. EP 4.22. Another wire PQ of length 1m, mass 2.5 g carries the same current but in the opposite direction. The wire PQ is free to slide up and down. To what height will PQ rise?

A circular coil of wire consisting of 100 turns, each of radius 8.0 cm carries a current of 0.40 A. What is the magnitude of the magnetic field B at the centre of the coil?