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

Answer:

$7.2\cdot 10^{-4} N/m$

Explanation:

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

$\frac{F}{L}=\frac{\mu_0 I_1 I_2}{2\pi r}$

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,

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