Question

Two long, parallel wires separated by 2.95 cm carry currents in opposite directions. the current in one wire is 1.70 a, and the current in the other is 3.00
a. (a) find the magnitude of the force per unit length that one wire exerts on the other. n/m (b) is the force attractive or repulsive? attractive repulsive

Answer 1

(a) the magnitude of force per unit length= 3.46 x 10⁻⁵ N/m

(b) The force is repulsive.

Explanation:

(a) The force per unit length between two conductors is given by

$F=\frac{uo}{4\pi} \frac{2 i1 i2}{r}$

i1= current in the first wire= 1.7 A

i2= current in the second wire = 3 A

r= distance between the wires= 2.95 cm=0.0295 m

$\frac{uo}{4\pi}$ = 10⁻⁷ Tm/A

so F= (10⁻⁷) (2 * 1.7 * 3 )/(0.0295)

F= 3.46 x 10⁻⁵ N/m

(b) since the wires are carrying the currents in the opposite directions, so the force between them is repulsive.