Two parallel wires question

Question

Two parallel wires separated by 4.0 cm repel each other with a force per unit length 2.0 × 10^-4 N/m. The current in one wire is 5.0 A.

(a) Find the current in the other wire.

(b) Are the currents in the same direction or in opposite directions?

Answer 1

To solve this problem, you can use the formula for the magnetic force per unit length between two long, parallel current-carrying wires. The formula is given by:

F/L= μ₀​I₁I₂​/(2πd)​

As for the direction of the currents, since the wires are repelling each other, it means that the currents are flowing in opposite directions (Use the screwdriver rule to figure out the direction of the magnetic field, and the RHR for the direction of force).