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

Answer

D

Explanation

The permeability of a ferromagnetic materialis not independent of magnetic field, `vec(B)=K_(m)vec(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 magnetizatio `vec(M)` increases linearly with `vec(B)`, even at small value of `B_(0)`. From the hysteresis curve, magnetic permeability is greater for lower field.