10 The horizontal component of the earth’s magnetic field
at a certain place is 3 0 ×10–5 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 1A 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