Chapter 22Current Electricity

Chapter 22Current Electricity

Milbank High SchoolMilbank High School

Sec. 22.1Current and CircuitsSec. 22.1Current 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

Electric CurrentsElectric 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

Electric CircuitsElectric Circuits

• Closed loop• Closed loop

Rate of Charge FlowRate of Charge Flow

• Coulomb

• Ampere

• PowerP = IV

• Example Problem Pg. 511

• Coulomb

• Ampere

• PowerP = IV

• Example Problem Pg. 511

Resistance and Ohm’s LawResistance and Ohm’s Law

• ResistanceR = V/I

Resistance (R) is the ratio of potential difference (V) to the current (I)

• Ohm’s Law

• Resistors

• Superconductors

• ResistanceR = V/I

Resistance (R) is the ratio of potential difference (V) to the current (I)

• Ohm’s Law

• Resistors

• Superconductors

Drawing Electric CircuitsDrawing Electric Circuits

• Schematic

• Parallel Connection

• Ammeter

• Series Connection

• Symbols

• Schematic

• Parallel Connection

• Ammeter

• Series Connection

• Symbols

Sec. 22.2Using Electric EnergySec. 22.2Using 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

Using Electric EnergyUsing 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 circuitE = I2Rt

• 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 circuitE = I2Rt

Transmission of Electric EnergyTransmission of Electric Energy

• Thermal energy is produced at a rate of

P = I2R

• 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 = I2R

• Used to calculate thermal energy loss in long-distance transmission

• Kilowatt-hour– Equal to 1000 watts delivered continuously for

3600 seconds (1 hour)