Question

A 100-m-long wire carrying a current of 4.0 A will be accompanied by a magnetic field of what strength at a distance of 0.050 m from the wire? (magnetic permeability in empty space µ0 = 4π x 10^-7 Tm/A)

Answer 1

The formula for calculating the magnetic field strength in a long straight wire is expressed as

B = μoI/2πr

where

B = magnetic field magnitude

μo = permeability of free space

I = magnitude of electric current current

r = distance

From the information given,

r = 0.05

I = 4

µ0 = 4π x 10^-7 Tm/A

π = 3.14

By substituting these values into the formula, we have

B = (4π x 10^-7 x 4)/2 x π x 0.05

B = 1.6 x 10^- 5 T

The magnetic field strength = 1.6 x 10^- 5 T