Chapter 22 Current Electricity

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Chapter 22Current Electricity

• Milbank High School

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Sec. 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 Ohms law

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Electric Currents

• Electric current
• A flow of charged particles
• Conventional current
• conductors
• Battery
• Photovoltaic cell

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Electric Circuits

• Closed loop

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Rate of Charge Flow

• Coulomb
• Ampere
• Power
• P IV
• Example Problem Pg. 511

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Resistance and Ohms Law

• Resistance
• R V/I
• Resistance (R) is the ratio of potential
  difference (V) to the current (I)
• Ohms Law
• Resistors
• Superconductors

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Drawing Electric Circuits

• Schematic
• Parallel Connection
• Ammeter
• Series Connection
• Symbols

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Sec. 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

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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 I2Rt

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Transmission 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)