Question

Two long, parallel wires are separated by a distance of 3.60 cmcm . The force per unit length that each wire exerts on the other is 4.80×10−5 N/mN/m , and the wires repel each other. The current in one wire is 0.620 AA .(a) What is the current in the second wire? (b) Are the two currents in the same direction or in opposite directions?

Answer 1

given,

distance between two parallel wires,r = 3.60 cm

Force per unit length = 4.80 x 10⁻⁵ N/m

current in one, I= 0.62 A

current in the second wire = ?

a) the magnitude of force per unit length between two wire is carrying currents is given by.

`(F)/(L)=(\mu_0I'I)/(2\pi r)`

we need to find I'

`I' = (2F\pi r)/(L\mu_0I)`

`I' = (2* 4.80* 10^(-5)\pi 0.036)/(4\pi * 10^(-7)* 0.62)`

I' = 13.93 A

b) If current are in same direction then they will attract each other and the current is in opposite direction they will repel.

hence, the current in both the wire is in opposite direction.