Question

A magnetic field of magnitude 1.30x10-3 T is measured a distance of 0.03 m from a long straight wire. What is the current through the wire?

Answer 1

`I=195A`

Step-by-step explanation:

According to the Biot–Savart law, the magnitude of a magnetic field created by the current in a long straight wire, is defined as:

`B=(\mu_0I)/(2\pi R)`

Where
`\mu_0` is the permeability of free space, I is the current circulating on the wire and R is the distance from the point where B is measured.

Solving for I:

`I=(2\pi BR)/(\mu_0)\\I=(2\pi(1.3*10^(-3)T)(0.03m))/(4\pi*10^(-7)(T\cdot m)/(A))\\I=195A`