Question

Two long straight parallel conductors carrying currents, exert a force on each other. Why ? Derive an expression for the force per unit length between two long straight parallel conductors carrying currents in opposite directions. Explain the nature of the force between these conductors.

With the help of a labelled diagram, explain the working of an ac generator. Obtain the expression for the emf induced at an instant 't'.

A long, straight horizontal wire X'X is held stationary and carries a current of 3.0 A. A square loop MNPS of side 10 cm, carrying a current of 1.0 A is kept near the wire X'X as shown in the figure. Find the magnitude and direction of the net magnetic force acting on the loop due to the wire.

Two long parallel straight wires A and B are 2·5 cm apart in air. They carry 5·0 A and 2·5 A currents respectively in opposite directions. Calculate the magnitude of the force exerted by wire A on a 10 cm length of wire B.