Find the magnetic field at a distance of 20 cm from a long, straight wire carrying a current of 10A.

Problem Statement: Find the magnetic field at a distance of 20 cm from a long, straight wire carrying a current of 10A.

Solution:

Given: current I =10 A
distance r = 20 cm = 0.2 m
Magnetic field B =?
We know, μ₀=4π x 10^-7

The magnetic field at a distance r from a long, straight wire carrying a current I, is expressed as
B = (μ₀I)/(2πr)

Here, putting all values,
B = (μ₀I)/(2πr)
=> B = (4π x 10^-7x 10)/ (2π.0.2) = 10^-5 T