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 the field if current in one of the wires is switched off?

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 straight segment OC(of length L meter) of a circuit carrying a current I amp is placed along the x- axis ( fig.). Two infinitely long straight wires A and B , each extending from z = -oo to +oo , are fixed at y = -a meter and y = +a meter respectively, as shown in the figure. If the wires A and B each carry a current I amp into the plane of the paper, obtain the expression for the force acting on the segment OC. What will be the force on OC if the current in the wire B is reversed?

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.

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 wire carrying current I and other carrying 2I in the sam direction produce a magnetic field B at the midpoint. What will be the field when 2I wire is swiched off?

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 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.

A current of 10 A flow around a closed path in a circuit which is in the horizontal plane as shown in the figure. The circuit consists of eight alternative arcs of radii r_(1)=0.08m and r_(2)=0.12m . Each subtends the same angle at the centre. An infinitely long straight wire carrying a current of 10 A is passing throgh the entre of the above circuit vertically with the direction of the current being into the plane of the circuit. What is the force acting on the wire at the centre due to the current in the circuit? What is the force acting on the arc AC and the straight segment CD due to the current at the centre?

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.