Question

Two long, straight, parallel wires of length 3.6 m carry parallel currents of 3.0 A and 1.6 A.

(a) If the wires are separated by a distance of 3.9 cm, what is the magnitude of the force between the two wires? __N

(b) Is this force attractive or repulsive?

(c) If the currents are in opposite directions (antiparallel), how do the answers to parts (a) and (b) change? What is the magnitude of the force between the two wires? ___N

Please explain equations in detail! :) The answer should be very small in Newtons.

Answer 1

(a) L = 36 m I_1 = 3.0 A I_2 = 1.6 A d = 0.039 m F = mu_0 I_1 I_2 L/2 pi d F = (4 pi times 10 ^7) (3) (1.6) (3.6)/2 pi (0.039) F = 8.86 times 10 ^-5 N (b) As current is parallel so force will be attractive (c) if current antiparallel then force magnitude will remain same but this will be repulsive F = 8.86 times 10 ^-5N Repulsive