Physics Notes

Electric Current

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Concepts:

(A detailed list of terms & objectives is available.)

• Concept Summary (PowerPoint) (download the PowerPoint file)
• Potential Difference
  • Electric current
    • Measuring current
  • Maintaining a potential difference - voltage sources
• Ohm's Law
  • Resistance
  • Using Ohm's Law to solve simple numeric problems
    • the Ohm's Law Triangle
  • Practice Quiz on Ohm's Law
• Electric shock
  • Effects
  • How to avoid electric shocks
  • What to do in case someone is shocked
  • Why do some electric plugs have 2 prongs and some have 3?
• Direct & Alternating Current
  • AC/DC conversions
    • diodes
  • Electron motion in a circuit
  • Where do the electrons come from in a circuit?
  • What carries the energy in an electric circuit?
• Electric Power
  • Calculating power, voltage, current, and resistance
    • Practice quiz on electric power
  • How much does it cost to run a light bulb?
    • Practice quiz on cost of electric energy

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Labs & Demos:

• Lab Activity: Bulbs & Batteries
• Experiment: Ohm's Law

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Supplements:

• Videodisc - The best From Conceptual Physics Alive!
  • Demo: Electric Potential (Side 4 - Chapter 2 - 0:34)
  • Caution on Handling Electrical Wires (Side 4 - Chapter 3 - 0.57)
  • Birds & High Voltage Wires (Side 4 - Chapter 4 - 0:34)
  • Ohm's Law (Side 4 - Chapter 5 - 2:39)
  • Alternating Current (Side 4 - Chapter 6 - 2:45)

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Links:

• CPSurf - Electric Current - an excellent set of annotated links keyed to your textbook.
• How Electricity Works - part of the amazing "How Stuff Works" web site
• Resistance at the Molecular Level Applet - an interactive animation to give you an idea of how resistance arises at the molecular level.
• Ohm's Law Simulation by Visual Physics
• Java Tutorial - Ohm's Law - a very nicely done interactive tutorial
• Vacuum Tube Diode Applet - demonstrates how a diode can convert AC to DC

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last update March 31, 2008 by JL Stanbrough