1. Chapter 22 Current Electricity Milbank High School

2. Sec. 22.1 Current and Circuits Objectives –Define an electric current and the ampere –Describe conditions that create current in an electric circuit –Draw circuits and recognize that they are closed loops –Define power in electric circuits –Define resistance and describe Ohm’s law Objectives –Define an electric current and the ampere –Describe conditions that create current in an electric circuit –Draw circuits and recognize that they are closed loops –Define power in electric circuits –Define resistance and describe Ohm’s law

3. Electric Currents Electric current –A flow of charged particles Conventional current –conductors Battery Photovoltaic cell Electric current –A flow of charged particles Conventional current –conductors Battery Photovoltaic cell

4. Electric Circuits Closed loop

5. Rate of Charge Flow Coulomb Ampere Power P = IV Example Problem Pg. 511 Coulomb Ampere Power P = IV Example Problem Pg. 511

6. Resistance and Ohm’s Law Resistance R = V/I Resistance (R) is the ratio of potential difference (V) to the current (I) Ohm’s Law Resistors Superconductors Resistance R = V/I Resistance (R) is the ratio of potential difference (V) to the current (I) Ohm’s Law Resistors Superconductors

7. Drawing Electric Circuits Schematic Parallel Connection Ammeter Series Connection Symbols Schematic Parallel Connection Ammeter Series Connection Symbols

8. Sec. 22.2 Using Electric Energy Objectives –Explain how electric energy is converted into thermal energy –Determine why high-voltage transmission lines are used to carry electric energy over long distances –Define kilowatt-hour Objectives –Explain how electric energy is converted into thermal energy –Determine why high-voltage transmission lines are used to carry electric energy over long distances –Define kilowatt-hour

9. Using Electric Energy Electric energy is converted to mechanical energy (motor) Electric energy converted to light (lamp) –Both of these get hot (some energy is converted to thermal energy) Heating resistors –Space heater, hot plate, iron –Act as resistors in a circuit E = I 2 Rt Electric energy is converted to mechanical energy (motor) Electric energy converted to light (lamp) –Both of these get hot (some energy is converted to thermal energy) Heating resistors –Space heater, hot plate, iron –Act as resistors in a circuit E = I 2 Rt

10. Transmission of Electric Energy Thermal energy is produced at a rate of P = I 2 R Used to calculate thermal energy loss in long-distance transmission Kilowatt-hour –Equal to 1000 watts delivered continuously for 3600 seconds (1 hour) Thermal energy is produced at a rate of P = I 2 R Used to calculate thermal energy loss in long-distance transmission Kilowatt-hour –Equal to 1000 watts delivered continuously for 3600 seconds (1 hour)