1. Science
Notes: Stnd 01
Date
Standard 01: 8.PS2.1
Magnetism and Electricity
Design and conduct investigations depicting the relationship between magnetism and electricity in electromagnets, generators, and electrical motors, emphasizing the factors that increase or diminish the electric current and the magnetic field strength.
Science and Engineering Practice(s)
Develop and Use Models, Obtain and communicate information, Construct Explanations
Crosscutting Concepts
Cause and Effect, Systems and Systems Models
I Can Statement
...I can explain and demonstrate cause and effect relationships
between magnetism and electricity.

2. Magnetism and Electricity
Notes
Stnd 01:
Magnetism and Electricity
Science
Magnetic Fields
An invisible magnetic field exists around all magnets. N S

3. One end is the North Pole. Other end is the South Pole.
Magnetic Fields
You can see the magnetic field lines by using fine iron filings.
Note: field lines are concentrated at the ends (called poles)
One end is the North Pole. Other end is the South Pole.
North Pole
South Pole

4. Magnetism and Electricity
Notes
Stnd 01:
Magnetism and Electricity
Science
North and South Poles
All magnets have these poles regardless of their shape.
If you cut a magnet in half, each half will still have these two poles (north and south)
Bar magnet
Horseshoe Magnet
Donut magnet

5. F.Y.I: Why Are Some Substances Magnetic?
All atoms have magnetic fields with north and south poles.
Atoms in objects are found in areas called domains.
If the poles line up facing the same direction, this makes the object magnetic.
If they don’t line up, it is not magnetic.

6. Magnetism and Electricity
Notes
Stnd 01:
Magnetism and Electricity
Science
Magnetic Forces
magnets exert force on other magnets
“Opposites attract”
(North & South pull towards each other) N S
“Like repels”
(North & North or South & South push away) N S

7. Electromagnets
Electric current in the wire produces a magnetic field which lines up atoms in the domains of the iron core forming an electromagnet.
Simple Electromagnet
Iron Core
Source of
Electricity
Solenoid
An electromagnet consists of a solenoid wrapped around an iron core attached to a source of electricity

8. (1) Move it faster or (2) Add more coils. Simple Electrical Generator
Electromagnetic Induction
Magnets and a coil of wire can induce (generate) electricity
The magnet has to move through the coil (solenoid)
… or the coil has to move through the magnet
To Increase the Current:
(1) Move it faster or (2) Add more coils.
Simple Electrical Generator
Coil of Wire
(Solenoid)
Bar Magnet

9. Rotational Generators
(very common)
Note: the magnet is stationary and the wire coil is rotating.
It also works if the wire is stationary and the magnet is moving
Rotational Generator
Magnet
Magnet
Wire Coil

10. How It Works All magnets have an invisible magnetic force field.
The bar magnet is pushed back and forth
through the solenoid
Simple Electrical Generator
The magnetic force field pushes the electrons from atom to atom in the wire creating electrical current.

11. F.Y.I.-Electromagnetic Induction
…is how most electricity is generated around the world.
These power plants all use magnets and coils of wire to make electricity
Nuclear Power Plant
Wind Turbines
Coal Power Plant
Hydroelectric Dam

12. F.Y.I.-Electromagnetic Induction
…is how most electricity is generated in cars, trains, boats, & planes
Each of these machines has a generator inside that creates electricity
Electrical Generator
(Alternator)
Consists of a magnet rotating through a
coil of wire

13. Electrical Motors
Electrical motors change electrical energy into mechanical energy.
In other words, they use electricity to make things move.
Most common movement: rotary motion
To Increase the Output (Torque):
(1) Use more current (2) Add more coils (3) Use stronger magnets

14. Are commonly used in a great variety of devices
Electrical Motors
Are commonly used in a great variety of devices
Blenders
RC (Toy) Cars
Hairdryers
Electric Shavers
Electric Fans
Washers and Dryers
Laptop Fans

15. Are commonly used in a great variety of machines
Electrical Motors
Are commonly used in a great variety of machines
Flying Drones
Underwater Drones
Robotic Explorers
Submarines
Electric Cars
Electric Trains

16. Electrical Motor Details
Various Types: AC motors, DC motors, induction motors, brushed motors, brushless motors, stepper motors, etc.
Three Motor Components: Stator, Rotor, Commutator,
What does the stator do? (Look it up online!)
What does the rotor do? (Look it up online!)
What does the commutator do? (Look it up online!)