Di­amagnetic materials are either metal or nonmetal materials that cannot be magnetized.

• A. False
• B. Sometimes
• C. True
• D. Not at all

Answer: (C)

Diamagnetic materials respond to an external magnetic field by creating a tiny magnetic moment that points opposite to the field. This makes them slightly repelled by the field. Crucially, this induced magnetization only exists while the external field is present, and it disappears when the field is removed. So they do not become permanent magnets. In that sense, saying they cannot be magnetized (in the sense of gaining lasting magnetization) is true. They can have a moment briefly when the field is on, but not keep it afterward. This applies to both metals and nonmetals.