Basics of Electricity Magic of Electrons 2011 Project

What is Electricity? • • Involves the movement of electrons Is invisible Provides light, heat, sound, motion. . . Has been practical for use over the last 100 years

History 2500 years ago, the Greeks rubbed amber with other materials. They discovered that this process would attract feathers and other lightweight materials to the amber.

History Ben Franklin suggested that. . . + . . . opposite charges attract and like charges repel. -

History Ben Franklin suggested that. . . opposite charges attract and like charges repel. The Law of Charges explains why the electrons continue to be bonded to the nucleus. + +

Electron Flow An electron from one atom can knock out an electron from another atom.

Electron Flow Electricity is created as electrons collide and transfer from atom to atom. Play Animation

What Makes Up Electricity? Let’s compare it to something we know --- Water!

Water Analogy Tank Faucet Pipe Tank = Battery Pipe = Wiring Faucet = Switch

Current: The flow of electric charge Tank (Battery) Faucet (Switch) Pipe (Wiring) When the faucet (switch) is off, is there any flow (current)? NO When the faucet (switch) is on, is there any flow (current)? YES

Current in a Circuit off on When the switch is off, there is no current. When the switch is on, there is current.

Voltage: The force (pressure) behind the flow of current Tank (Battery) Faucet (Switch) Pipe (Wiring) When the faucet (switch) is off, is there any pressure (voltage)? YES – Pressure (voltage) is pushing against the pipe, tank, and the faucet. When the faucet (switch) is on, is there any pressure (voltage)? YES – Pressure (voltage) pushes flow (current) through the system.

Voltage in a Circuit off on The battery provides voltage that will push current through the bulb when the switch is on.

Resistance: The opposition to the flow of current. Tank (Battery) Faucet (Switch) Pipe (Wiring) What happens to the flow (current) if a rock gets lodged in the pipe? Flow (current) decreases.

Resistance in a Circuit Resistor off on Resistors are components that limit the flow of electricity. Reducing current causes the bulb to become more dim.

Types of Electricity (You might already know these!)

Types of Electricity Static Electricity The electrical charge an object develops as a result of having an unequal number of protons and electrons. Current Electricity The movement of electrons through a conductor.

Static Electricity • Uncontrollable Electricity • Lightening • Static Cling • Wool socks on a carpet “shocks”

Current Electricity Two Types: Direct Current (DC) Alternating Current (AC)

Direct Current The electrons flow in the same direction all the time, from negative to positive. - +

Direct Current Comes from • Batteries • Converted from Alternating Current Used for electronic devices including • Computers • i. Pods • Cell phones • Anything that has a “charger”

Alternating Current The electrical current (movement of electrons) changes direction.

Alternating Current Comes from Generators • Coal burning and nuclear power plants • Hydroelectric power plants • Wind and solar generators Used for • Motors • Heaters • Lights • Anything that plugs into the wall

Image Resources Microsoft, Inc. (2008). Clip Art. Retrieved September 10, 2008, from http: //office. microsoft. com/en-us/clipart/default. aspx