Question

The magnetic field due to a utility wire is 0.10 mT when you are at a distance of 10 meters from it. What current (in Amperes) flows through the wire?

Answer 1

I = 5000 A

Step-by-step explanation:

We will use Ampere's Law to calculate the current:

`B = (\mu I)/(2\pi r)\\\\`

where,

B = Magnetic Field Strength = 0.1 mT = 1 x 10⁻⁴ T

μ = Permeability of Free Space = 4π x 10⁻⁷ N/A²

I = Current = ?

r = radius = 10 m

Therefore,

`1\ x\ 10^(-4)\ T = ((4\pi\ x\ 10^(-7)\ N/A^2)(I))/(2\pi(10\ m))\\\\I = ((1\ x\ 10^(-4)\ T)(2\pi (10\ m)))/(4\pi\ x\ 10^(-7)\ N/A^2)`

I = 5000 A