Assertion: The permeability of a ferromagnetic material is independent of the magnetic field.
Reason: Permeability of a material is a constant quantity.

Options

A. If both the assertion and reason are true and reason is a true explanation of the assertion.
B. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
C. If the assertion is true is true but reason is false.
D. If both the assertion and reason are false.

Answer

D

Explanation

The permeability of a ferromagetic material is not independent of magnetic field, `vec(B)=K_(m)vec(B_(0))`.
`B_(0)` is applied field. The total magnetic field `vec(B)` inside a ferromagnet may be `10^(3)` or `10^(4)` times the applied field B_(0). The permeability `K_(m)` of a ferromagnetic material is not constant, neither the field `vec(B)` nor the magnetization `vec(M)` increases linearly with `B_(0)`. Even at small value of the hysteresis curve, magnetic permeability is greater for lower field.