An iron rod is placed parallel to magnetic field of intensity `2000 Am^-1`. The magnetic flux through the rod is `6xx 10^-1` Wb and its cross-sectional area is `3 cm^2`. The magnetic permeability of the rod in Wb `A^-1 m^-1` is

Options

A. `10^-1`
B. `10^-2`
C. `10^-3`
D. `10^-4`

Answer

C

Explanation

According to question, magnetic permeability of the rod is given by `mu_(r) = B/B_0`
where, B = magnetic field without iron rod
`B_0` = magnetic field after insertion of iron rod
So, `mu = B/(2000Am^-1)`
[`because B.A= phi Rightarrow B = phi/A=(6xx10^-4Wb)/(3xx10^^-4 m^2)=2Wbm^-2`]
so, `mu_r=2/2000=10^-3`