Question

Which statement about electromagnets is incorrect?
(a) They have a core of steel.
(b) They remain magnets when electricity is switched off.
(c) They can function only when electricity is switched on.
(d) They can be used to lift heavy iron loads.

Answer 1

Statements (a) and (b) are incorrect.

The core of electromagnets must be of soft iron.
Electromagnets behave like magnets only when current passes through it.