- In an electric circuit, an energy source provides electrons with energy. Electrons are transported via a conductor to where their energy is transferred. Then they are transported back to the energy source to be re-energized.
- Current is the flow of charge: the total amount of charge moving past a point in a conductor divided by the time taken.
- The formula for current is I=Q/t, where I is current in amperes (A), Q is the charge in coulombs (C), and t is time in seconds.
- 1 ampere = 1 coulomb of charge moving through a point every second.
- Current actually flows from - to +, but in conventional current (model of positive charge flow) current flows from + to -.
- Ammeter is a device that measures current.
- DC or direct current is type of current that flows in a single direction from the power supply to the load.
- Electric Potential Difference (Voltage) is the electrical potential energy for each coulomb of charge.
- Formula for voltage is: V=E/Q, where E is the energy required to increase the electric potential of a charge, Q.
- The formula for the energy transferred by charge flow is E=VIt, where E is energy in joules, V is the potential difference in volts, I is the current in amperes, and t is time in seconds.
- A voltmeter is used to measure electric potential difference (voltage).
Pictures and Videos
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| Some of the various symbols used in electric circuit diagrams. |
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| A diagram demonstrating a conventional current. |
Some other useful websites:
http://en.wikipedia.org/wiki/Electric_current
http://www.physicsclassroom.com/class/circuits/u9l2c.cfm
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