Question

The magnetic induction and the intensity of magnetic field inside an iron core of an electromagnet are `1 Wbm^(-2)` and `150Am^(-1)` respectively. The relative permeability of iron is : `(mu_(0)=4pixx10^(-7)"henry"//m)`
A. `(10^(5))/(6 pi)`
B. `(10^(5))/(pi)`
C. `(10^(5))/(3 pi)`
D. `(10^(5))/(5 pi)`

Answer 1

Correct Answer - B
The permeability is given by `mu = B//H`
`:.` Relative permeability
`mu_(r)=(mu)/(mu_(0))=(B)/(mu_(0)H)=(10)/(4pixx10^(-7)xx250)=(10^(5))/(pi)`