Question

In a physics lab a student discovers that the magnitude of the magnetic field in a specific location near a long wire is 4.735 microTesla. If the wire carries a current of 86.182 A, what is the distance from the wire to that location ?

Answer 1

We would apply the formula for calculating the magnitude of a magnetic field which is expressed as

B = μoI/2πr

where

μo is the permeability of free space and its value is 4π x 10^- 7 Tm/A

B is the strength of the magnetic field

I is the current

r is the distance of the wire

From the information given,

I = 86.182

B = 4.735 x 10^-6 T

By substituting these values into the formula, we have

4.735 x 10^-6 = 4π x 10^- 7 x 86.182/2πr

4.735 x 10^-6 = 0.0000172364/r

r = 0.0000172364/4.735 x 10^-6

r = 3.64 m

the distance from the wire to that location is 3.64 m