Permanent magnets are always on.

Electromagnets are different.

With a simple switch, magnetic force can appear and disappear instantly.

That single capability powers cranes, electric bells, relays, motors, speakers, and countless modern technologies.

In this experiment, we explore three remarkable applications of electromagnets.

An electromagnet combines:

• A magnetic material
• A coil of wire
• Electric current

When current flows, the magnetic field appears.

When current stops, the magnetic field weakens or disappears.

The ability to control magnetic force makes electromagnets one of the most useful inventions in science and engineering.

Application 1 — A Magnetic Crane

The first demonstration highlights the practical power of electromagnets.

An iron nail wrapped with copper wire was connected to a battery through a switch.

When the switch was turned on:

• The electromagnet attracted paper clips.
• The clips could be lifted from one location.

When the switch was turned off:

• The magnetic field disappeared.
• The clips fell immediately.

The same principle is used in industrial cranes.

Large electromagnets can lift enormous masses of ferrous material and release them instantly when the current is switched off.

The force is not merely strong—it is controllable.

Application 2 — Building a Compass from an Electromagnet

Can an electromagnet behave like a compass?

To investigate, the entire circuit was suspended using a thread so that it could rotate freely about a vertical axis.

The electromagnet itself remained horizontal and free to turn.

When the current was switched on, the system slowly rotated.

Eventually it settled into a preferred orientation.

The electromagnet aligned itself with Earth's magnetic field, just as a permanent magnet does.

The experiment demonstrates that:

An electromagnet is not merely similar to a permanent magnet—it behaves as one.

When current flows, the coil acquires a north pole and a south pole.

The Earth then exerts a torque on it.

The result is a compass whose magnetic poles can be created and destroyed with a switch.

Application 3 — Creating Motion

The third demonstration converts magnetic force into vibration.

A paper clip was attached to the end of a spring.

One end of the spring was fixed.

The other end was free to move.

An electromagnet was placed nearby.

When the magnetic field was repeatedly switched on and off:

• The paper clip was attracted.
• The spring stretched and recoiled.
• Oscillations appeared.

Magnetic force had been transformed into mechanical motion.

This simple setup reveals the basic idea behind many electro-mechanical devices.

One famous application is the electric bell.

In an electric bell:

1. Current flows.
2. An electromagnet attracts a metal arm.
3. The motion breaks the circuit.
4. Current stops.
5. The arm returns.
6. The circuit reconnects.

The process repeats rapidly.

The result is continuous vibration and ringing.

Spring oscillator demonstrates the same underlying principle.

What Makes Electromagnets Special?

Permanent magnets are useful.

Electromagnets are programmable.

They allow us to control:

• When force appears
• When force disappears
• How strong the force becomes
• How long the force acts

This controllability is what makes modern electrical technology possible.

A Deeper Realization

Across all three demonstrations, the same idea appears repeatedly:

Electricity creates magnetism.

But something even more profound is happening.

Electricity is not merely creating a magnetic field.

It is creating a force that can be turned on, turned off, redirected, and timed precisely.

That ability to control force is the foundation of modern technology.

Can you invent a fourth use for an electromagnet?