Question

What is the relative permeability of an air-core inductor, if its self-inductance increases from 0.5 mH to 50 mH due to the introduction of an iron core into it?

(a) 100

(b) 0.1

(c) 10000

(d) 0.0001

This question was posed to me in an interview for internship.

Question is taken from Electromagnetic Inductance in chapter Electromagnetic Induction of Physics – Class 12

Answer 1

Right option is (a) 100

The explanation: μr = \(\frac {\mu }{\mu_0}\)

μr = \(\frac {L}{L_0}\)

μr = \(\frac {50}{0.5}\)

μr = 100