Question

Determine the magnitude and direction of the force between two parallel wires 20m long and 4.0cm apart (center-to center) each carrying 30A in the same direction. The radius of each wire is 1.3mm.

Answer 1

The magnitude and direction of the force is 0.09 N, attractive

Step-by-step explanation:

The magnitude of the force is:

`F=(u_(o)I_(1)I_(2)L_(2) )/(2\pi d)`

Where

d = distance = 4 cm = 0.04 m

uo = constant = 4πx10⁻⁷Tm/A

I₁ = 30 A

I₂ = 30 A

L = 20 m

Replacing:

`F=(4\pi x10^(-7)*30*30*20 )/(2\pi *0.04) =0.09N` attractive

Answer 2

Force on each conductors = 4x10^-3 N

The force between the wires are attractive so the direction of this force is towards each other