Both bar magnets and electromagnets have magnetic fields and attract iron materials. However, electromagnets can be turned on and off by controlling the electric current, while bar magnets maintain their magnetism permanently. Additionally, electromagnets can be made stronger by increasing the number of wire coils or electric current, whereas the strength of bar magnets cannot be controlled.

1. How Does an Electromagnet
Work?
S5P3d. Compare a bar magnet to an
electromagnet

2. What is a Magnet?
• An object that attracts certain metals,
mainly iron
• Magnetism decreases with distance from
an object
•Permanent magnets- keep their magnetism
for a long time
•Temporary magnets- lose their magnetism
after a short time

3. Magnetic Fields
The space in which a magnetic force can act is called a magnetic field.
Magnetic Poles- two areas of on a magnet in which the magnetic force is the
greatest.

4. The Earth as a Magnet
The Earth behaves like a giant sized bar magnet. The center of the Earth is made
up of iron. When the Earth spins, the iron particles line up creating a gigantic
magnetic field.

5. Electricity and Magnetism
•Electricity can produce magnetism
•Magnetism can produce electricity
•Together, magnetism and electricity, can produce
energy of motion
•An electromagnet is a strong temporary magnet
that uses electricity to produce magnetism. You use
them everyday in blow dryers and video games.

6. How Does Electricity Produce
Magnetism?
-An electric current passes through a wire
or other conductor
-The current produces a weak magnetic
field around the wire
-If the wire is wrapped around iron, the
iron becomes magnetized
-This makes the magnetic field stronger

7. Using Electromagnets
Magnets Electromagnets
Attract materials Attract materials
made of iron made of iron
Have magnetic fields Have magnetic fields
Magnetic force can be
controlled

8. Electromagnets
• Increasing the number of wire coils or the amount of
current through coils increases the STRENGTH
• Can be small and strong
• Can be turned on and off
• Cranes, MRIs, and the Bullet Train are useful
electromagnets
•Electromagnets are in blenders, computers, and doorbells
Brainpop- Electromagnets

9. Motors
A motor is a device that changes electrical energy
into energy of motion. They contain a permanent
magnet and an electromagnet.
“When a motor is turned on, electric current passes
through a wire wrapped around an iron core. The
magnetic field of this electromagnet interacts with
the magnetic field of the permanent magnet. The
like poles of each magnet repel each other and the
unlike pole attract each other, producing motion.”

10. Generating Electricity
Brainpop- Electomagnetic Induction
Generator – a device that uses magnetism to
convert energy of motion into electrical energy
• giantgenerators make electricity we use
• have powerful permanent magnets and huge coils of wire
• current is produced when the coils move across the magnetic
field
• stronger magnet or more coils increases amount of electricity
made
• energy to move coils comes from burning coal, nuclear fuels,
steam, falling water, or blowing wind

11. Electromagnets
Complete a Venn diagram
comparing a bar magnet with
an electromagnet.