Question

For electric forces we say that "likes repel, unlikes attract," but for the magnetic forces between two parallel current-carrying wires, we can say "likes attract, unlikes repel." To get a feel for the size of the effects, calculate the magnitude of the force per meter (that is, the force on one meter of wire) if I1= I2 = 12 amperes, and the distance between the wires is d = 4 centimeter.

Answer 1

`7.2\cdot 10^(-4) N/m`

Step-by-step explanation:

The magnetic force between two current-carrying wires is given by:

`(F)/(L)=(\mu_0 I_1 I_2)/(2\pi r)`

where

`\mu_0` is the vacuum permeability

I1 and I2 are the two currents

r is the distance between the wires

Here we have:

`I_1 = I_2 = 12 A\\r = 4 cm = 0.04 m`

Substituting into the equation,

`(F)/(L)=((4\pi \cdot 10^(-7))(12)(12))/(2\pi (0.04))=7.2\cdot 10^(-4) N/m`