2.  Electrical circuit: a closed loop where charged particles flow  Electrical current: a flow of charged particles (e - )  Direct current (DC): a flow of charged particles in one direction only  Alternating current (AC): a flow of charged particles in either direction (1 st in one direction, then the other)

3.  The amount of electrons that pass a given point in one second.  Current = I  Unit = Ampere (amp)  1 ampere = 6,250,000,000,000,000,000 (6.25 x 10 18 ) electrons passing a point in 1 second  1 amp = 1,000 mA

4.  The electrical pressure or force  Voltage = V  Unit = volts  Sometimes referred to as electric potential difference  Compare to water in a pipe: water = e - pressure = voltage

5.  The work performed by an electrical current  Power = P  Unit = watt

6.  The degree to which a conductor hinders the flow of charged particles  Resistance = Ohm  Unit = Ω  No conductor is perfect. Some current is lost (usually to heat)

7.  Ohm's law = the current through a conductor between two points is directly proportional to the voltage across the two points.  Formulas: P = I x VP = energy/time V = I x R I = V / R R = V / I