A long straight wire wire 1 has a current of 5 Amps running

A long straight wire, wire 1, has a current of 5 Amps running in the -x direction on the x axis. 2 meters \"above\" the x axis, in the x-y plane, a long wire, wire 2, with a current of 10 Amps runs in the +x direction. What is the force per unit length on wire 1?

a.10 x 10-6 N/m in the +y direction

b. 5 x 10-6 N/m in the -y direction

c.5 x 10-6 N/m in the +y direction

d.10 x 10-6 N/m in the -z direction

Solution

Here ,

for the force per unit length

F = u0 * I1 * I2/(2pi * d)

F = 4pi *10^-7 * 5 * 10/(2pi * 2)

F = 5 *10^-6 N

as the current in wires is in oposite direction

wires will repel

the correct option is

c.5 x 10-6 N/m in the +y direction