~Physics Notes~ =): Notes on Current electricity

1. Current
- Symbol: I
- Definition: Rate of charge flow

(Total amount of charge moving past a point in a conductor divided by time taken)

- Unit: C/s or Ampere (A)

The above figure shows the flowing of electrons~ If there are 5 coulombs(C) of electrons flowing through a conductor, then the current is 5 C/s or simply 5A. \(^0^)/

2. Conventional current: current flow from (+) terminal to (-) terminal
    When we consider current as flow of electrons,
          current will then be flowing from (-) terminal to (+) terminal.

    Animation of conventional current and electron flow:

http://www.mi.mun.ca/users/cchaulk/eltk1100/ivse/ivse.htm

3. Ammeter

- used to measure current

- have to be connected serially

- have to be an excellent conductor to prevent energy lost due to its addition to the circuit
NOTE: DON'T let too much current passing through it & DON"T connect the mater leads in reverse!!!

4. Two types of current:
a. Direct current (DC) - flows in a single direction from power supply through conductor to a load.

b. Alternating current (AC) - electrons periodically reverse the direction of their flow

5. Circuit

- complete path from negative side of power supply to the positive side

6. Different circuit symbols:

7. Voltage

- Symbol: V

- Definition: Electric potential difference

(electrical potential energy for each coulomb of charge in a circuit)

If a unit of electrical charge were placed in a location, the voltage indicates the potential energy of it at that point. In other words, it is a measurement of the energy contained within an electric field, or an electric circuit, at a given point.

- Unit: J/s or volt (V)
1 volt - electrical potential difference between two points if 1 joule of work (J) is required to move one coulomb (C) of charge between the points.

8. Energy transferred by charge flow is:

E = VIt

explanation: