Question

Two long, parallel wires are separated by a distance of 2.00 cm . The force per unit length that each wire exerts on the other is 3.60×10^−5 N/m , and the wires repel each other. The current in one wire is 0.640 A.
a. What is the current in the second wire?
b. Are the two currents in the same direction or in opposite directions?

Answer 1

Answer:

a) current in the second wire is 5.60A

b) opposite directions

Explanation:

a) We need to find the current of wire, the magnitude of the force per unit length between the two wires carrying current I and I¹ is given by

$\frac{F}{L} = \frac{U_0I^1}{2\pi r} \\\\I^1 = \frac{F2\pi r}{LU_0I}$

$= (3.6 * 10^-^5)\frac{2\pi (0.02)}{4\pi * 10^-^7)(0.64)} \\= 5.60A$

b) knowing that for a two parallel conductor carrying current in the same direction attracts each other, and for a two parallel conductors carrying carying current in opposite direction repels eachother.

therefore, since the two wire repel each other then the current in the second wire must flow in the opposite direction of the current in the first wire.