Question

A long, straight wire (radius = 2.0 mm) carries a current of 2.0 A distributed uniformly over a cross section perpendicular to the axis of the wire. What is the magnitude of the magnetic field at a distance of 1.0 mm from the axis of the wire?

Answer 1

Answer: The magnetic field is 4×10^-4T

Step-by-step explanation:

Using the magnetic field equation

B=μI/2πr

B= magnetic field =?

l= current in the wire=2.0A

r= distance from the axis of wire=1.0mm= 0.001m

μ=magnetic permeability =4π×10^-7N/m

B= (4π×10^-7 × 2.0)/(2π × 0.001)

B= 4×10^-4T

Therefore the magnetic field is 4×10^-4T