Which one of the following materials is ferromagnetic?

SOLUTION

Explanation:

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.
• Example: Iron, cobalt, nickel, gadolinium, and alloys like alnico.

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.
• Example: Manganese, aluminium, chromium, platinum, etc.

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.
• Examples: Bismuth, copper, lead, zinc, etc.

Hence, Nikel is only ferromagnetic material in the above options.