1. Electricity and Magnetism
Gateway To Technology®
Unit 4 – Lesson 4.1 – What is Electricity?
Electricity and Magnetism

2. Electricity and Magnetism
Gateway To Technology®
Unit 4 – Lesson 4.1 – What is Electricity?
Electricity and Magnetism
What is a Magnet?
North and South Poles of a Magnet
Types of Magnets
The Earth as a Magnet
Electromagnets
Electromagnetic Induction
Motors
Generators

3. Electricity and Magnetism
Gateway To Technology®
Unit 4 – Lesson 4.1 – What is Electricity?
What is a Magnet?
An object that is surrounded by a magnetic field and has the property of attracting iron or steel

4. Electricity and Magnetism
Gateway To Technology®
Unit 4 – Lesson 4.1 – What is Electricity?
Where are Magnets?
Magnets. . .
Generate electricity
Image courtesy of DOE/NREL
Image courtesy of DOE/NREL
Are in motors
Generate electricity: Turbines are turned at power plants by heated steam, water pressure, etc., to spin a turbine surrounded by magnets to generate electricity. Students will make a generator in an upcoming activity.
Motors spin because of the magnetic field that is created from electricity. Students will create a motor in an upcoming activity.

5. Electricity and Magnetism
Gateway To Technology®
Unit 4 – Lesson 4.1 – What is Electricity?
Where are Magnets?
Magnets. . .
Power car windows & locks
Image courtesy of NASA
Are used in Magnetic Resonance Imaging (MRI)
Power windows use a small motor, and power door locks use a solenoid. The clicking noise heard when the mechanisms lock or unlock is the release and activation of an electromagnet. Students will create an electromagnet in an upcoming activity.

6. North and South Poles of a Magnet
Electricity and Magnetism
Gateway To Technology®
Unit 4 – Lesson 4.1 – What is Electricity?
North and South Poles of a Magnet
Magnets have a north and south pole.
If a magnet is broken into smaller pieces, each piece will still have a north and south pole.
Opposite poles attract, like poles repel. N S N S S N N S N S N S N S N S N S

7. Electricity and Magnetism
Gateway To Technology®
Unit 4 – Lesson 4.1 – What is Electricity?
Types of Magnets
Magnets in Nature
Magnetite is a mineral that is naturally magnetic.
Human-Made Magnets
Some materials can be magnetized when placed near a strong magnetic field.
Soft magnetic materials (Iron)
Hard magnetic materials (Cobalt, Nickel)
Electromagnets
Magnets can be made by passing a current through a coil of wire.
U.S. Geological Survey / photo by Andrew Silver
Magnetite was created by proximity to the Earth’s magnetic field.
Most magnets are made using current, vibration, and heat.
Soft magnetic materials are easily magnetized, but also lose magnetism easily. Hard magnetic materials are difficult to magnetize, but tend to stay magnetized.
Almost all magnetic materials are alloys, which are combinations of different elements. These alloys contain naturally magnetic elements.

8. Electricity and Magnetism
Gateway To Technology®
Unit 4 – Lesson 4.1 – What is Electricity?
The Earth as a Magnet
The Earth is a large magnet.
North Pole
South Pole
Compasses work as a result of the Earth’s magnetic field.

9. Electricity and Magnetism
Gateway To Technology®
Unit 4 – Lesson 4.1 – What is Electricity?
Electromagnets
Magnets are created by passing a current through a wire.
Electromagnets are generally wire wrapped around an iron core.
Electromagnets are turned on and off when the current is switched on and off.

10. Electricity and Magnetism
Gateway To Technology®
Unit 4 – Lesson 4.1 – What is Electricity?
Image Resources
Microsoft, Inc. (2008). Clip Art. Retrieved October 20, 2008, from
U.S. Geological Survey Photographic Library (USGS). (2006). Retrieved October 20, 2008, from
National Renewable Energy Laboratory (2008). Photographic information eXchange. Retrieved October 21, 2008, from