Question

Two parallel wires separated by 3.55 cm repel each other with a force per unit length of 1.70 10-4 N/m. The current in one wire is 4.80 A.
(a) Find the current in the other wire.
(b) Are the currents in the same direction or in opposite directions? the same direction opposite directions
(c) What would happen if the direction of one current were reversed and doubled?

Answer 1

Explanation:

Given that,

Distance between two parallel wires, d = 3.55 cm

Force per unit length, $F/L=1.7\times 10^{-4}\ N/m$

Current in one wire, I = 4.8 A

(a) The force acting per unit length in the wire is given by :

$\dfrac{F}{L}=\dfrac{\mu_oI_1I_2}{2\pi d}$

Substituting all the values in above formula to find I₂ as:

$1.7\times 10^{-4}=\dfrac{4\pi \times 10^{-7}\times 4.8I_2}{2\pi \times 3.55\times 10^{-2}}$

$I_2=6.28\ A$

(b) Since, it is given that the two conductors repel each other, it means that the current is flowing in opposite direction.

(c) If the direction of current is reversed, they will start attracting towards each other and it the one current is doubled, the force per unit length will gets doubled.