Question

A conductor of length 2 m carrying current of 2 A is held parallel to an infinitely long conductor carrying current of 10 A at a distance of 100 mm. Find the force on small conductor. 

Answer 1

We know that force per unit length of short conductor due to long conductor is given by

∴ Total force on length l of the short conductor is

Force is attractive if the direction of current is same in both the parallel conductors and is repulsive if the direction of current is opposite in two parallel conductors.