Question

Two long, parallel wires, fixed in space, carry currents I₁ and I₂. The force of attraction has magnitude F. What currents will give an attractive force of magnitude 4F?

(A) 2I₁ and ½I₂ 

(B) I₁ and ¼I₂ 

(C) ½I₁ and ½I₂ 

(D) 2I₁ and 2I₂ 

(E) 4I₁ and 4I₂

Answer 1

The correct option is: (D) 2I₁ and 2I₂ 

Explanation:

Two parallel wires, each carrying a current I, repel each other with a force F. If both currents are doubled, the force of repulsion is 4F.