Question

What is the permeability of free space?

(a) 4  * 10^-6

(b) 4  * 10^-7

(c) 4  * 10^-8

(d) 4  * 10^-9

This question was posed to me by my college professor while I was bunking the class.

My query is from Ferro, Para and Dia Magnetic Materials topic in division Magnetic & Insulating Materials of Engineering Material & Metallurgy

Answer 1

Correct choice is (b) 4  * 10^-7

The explanation is: Permeability is defined as the ability of a material to form a magnetic field within itself. The permeability of free space is denoted by  and has a constant value of 4  * 10^-7 H m^-1.