9.3 Electromagnetism

Electromagnets are stronger than permanent magnets.

Electromagnets can be switched on and off as needed.

Permanent magnets cannot attract non-magnetic metals.

Electromagnets do not require electric current to function.

Steel is easier to magnetise and demagnetise repeatedly.

Steel is a better conductor of electricity than iron.

Steel retains its magnetism longer than pure iron.

Steel is not magnetic unless electricity is applied.

The electromagnet becomes a permanent magnet.

The strength of the electromagnet increases.

The poles of the electromagnet are reversed.

The electromagnet stops working completely.

To insulate the coil and prevent energy loss

To store electrical energy as potential energy

To amplify the magnetic field produced by the coil

To maintain a constant magnetic field without electricity

The coil becomes a permanent magnet.

The core gets demagnetised and breaks the circuit.

The hammer continues to hit the bell from momentum.

The coil is permanently magnetised and completes the circuit.

It attracts only non-magnetic materials.

It produces a stronger magnetic field.

It retains its magnetism without electricity.

It is only made of copper and aluminium.

Reversing the wire connections to the power source

Replacing the iron core with a steel core

Wrapping the coil in the opposite direction

Switching the direction of current flow

It is made of non-magnetic materials.

It has a magnetic field that is always present.

It requires electricity to work.

It does not have poles.

Place a magnet in a wire loop and apply heat.

Wrap a wire around a magnetic material and pass electric current through it.

Rub a metal object with a magnet repeatedly.

It becomes stronger.

It remains permanently magnetised.

It loses most of its magnetism.

It changes poles automatically.