Which of the following is not a magnetic material?

Question

Question

This question was previously asked in

SSC Steno Previous Paper 13 (Held on: 7 Feb 2019 Shift 2)

Answer 1

CONCEPT:

Diamagnetic Substance:

Diamagnetic substances are those which develop feeble magnetization in the opposite direction of the magnetizing field.
Such substances are feebly repelled by magnets and tend to move from stronger to weaker parts of a magnetic field.
Magnetic susceptibility is small and negative i.e. -1 ≤ χ ≤ 0.
Examples: Bismuth, copper, lead, zinc, etc.

Paramagnetic substances:

Paramagnetic substances are those which develop feeble magnetization in the direction of the magnetizing field.
Such substances are feebly attracted by magnets and tend to move from weaker to stronger parts of a magnetic field. Therefore option 2 is incorrect.
Magnetic susceptibility is small and positive i.e. 0< χ.
Example: Manganese, aluminum, chromium, platinum, etc.

Ferromagnetic substances:

Ferromagnetic substances are those which develop strong magnetization in the direction of the magnetizing field.
They are strongly attracted by a magnet and tend to move from weaker to the stronger part of a magnetic field.
Magnetic susceptibility is very large and positive i.e. χ > 1000.
Example: Iron, cobalt, nickel, gadolinium, and alloys like alnico.

EXPLANATION:

From the above options, only wood does not have unpaired electron spins that can line up with a magnet, and so it is a non-magnetic material.