The horizontal component of the earth's magnetic field at a certain place is `2.5xx10^(-5)T` and the direction of the field is from the geographic south to the geographic north. A very long straight conductor is carrying a steady current of 0.5 A. What is the force per unit length on it when it is placed on a horizontal table and the direction of the current is (a) east to west, (b) south to north?

Answer

(a) `1.25xx10^(-5)N`, (b) 0 N