Question

Two parallel wires in free space are 10 cm apart and each caries a current of 10 A in the same direction. The force exened by one wire on the other, per metre length is 

(a) 2 x 10^-1 N. repulsive 

(b) 2 x 10^-7 N,repulsive 

(c) 2 x 10^-4 N, attractive 

(d) 2 x. 10^-7 N, attractive

Answer 1

Correct option  (c) 2 x 10^-4 N, attractive 

Explanation:

Distance between two parallel wires (x) = 10 cm =0.1 m;

Since the current is flowing in the same direction, therefore the force will be attractive.