1. Circuits Notes Write everything in white and offwhite

2. What is electricity? Electric current – flow of electrons through a wire. Electric current – flow of electrons through a wire. Current (I) is measured by how many electrons pass a point during each second Current (I) is measured by how many electrons pass a point during each second Ampere – amount of current flowing in one second Ampere – amount of current flowing in one second

3. Parts of a Circuit A source of electrons A source of electrons Load or resistance (light bulb, heater, blender, etc) Load or resistance (light bulb, heater, blender, etc) Wires Wires Switch Switch

4. Sources of electrons Electrochemical cell Chemical reactions cause a flow of Electrochemical cell Chemical reactions cause a flow of electrons Two types Dry cell – batteries in your Ipod Wet cell – car battery Generator – uses magnets Hydroelectric Generator – uses magnets Hydroelectric Fossil fuel burning Nuclear

5. Load or resistance Load – device that uses the electrical energy Load – device that uses the electrical energy Light bulb, heating coils in a toaster, microwave oven Resists the flow of electrons Resists the flow of electrons Electrical energy converted into heat, light, or mechanical energy Electrical energy converted into heat, light, or mechanical energy

6. Wires Wires provide a path for electrons to flow Wires provide a path for electrons to flow Conductors – materials that electrons can move through easily Conductors – materials that electrons can move through easily ex. – copper, gold, silver Insulators- Insulators- electrons can’t move easily ex. – wood, cotton, rubber, glass

7. Insulation around Wires Two reasons Two reasons Electricity in wires can’t be transferred to a human Wires can’t touch each other and short out – causing a fire

8. Direct current Electrons flow in one direction from - terminal to + terminal Electrons flow in one direction from - terminal to + terminal Examples: Examples: AAA batteries Car battery

9. Alternating current Electricity changes direction continuously Electricity changes direction continuously Changes direction at speed of about 60 times per second (Hz) Changes direction at speed of about 60 times per second (Hz) Electric energy is transferred. Electrons stay in place. Electric energy is transferred. Electrons stay in place. Advantage: Advantage: Can travel over great distances at high voltages

10. AC DC Adaptors Take AC from wall and change to DC for your electronics Take AC from wall and change to DC for your electronics Important info: Voltage/Current from wall, Voltage/Current to device Important info: Voltage/Current from wall, Voltage/Current to device

11. Homework: Go find an AC DC adaptor at home. Record the Input voltage and current AND the Output voltage and current. Go find an AC DC adaptor at home. Record the Input voltage and current AND the Output voltage and current.