Electricity

							Electricity

Chapter 19 & 20
Current Electricity
Circuit- A continuous conducting path
Electric Current- The net amount of charge passing thru
a circuit at a point in a unit of time
      - I = the symbol for current
      - amperes – amp (A) – the unit for current
      - 1 ampere is 1 coulomb per second

I = q/t
              Current Movement

Conventional Current
      - current moves from positive to negative


Electron flow current
      - current moves from negative to positive


* Same info
             Electrical Potential

-Pressure of Flow                - voltage
-Potential difference            - electromotive force
-1 volt is the electrical potential difference between two
points if it takes 1 joule of work per coulomb to move a
positive charge from 1 point to another



V = W/q                 E = VIt
E = qV                  q = It
                     Resistance
-opposition to electron flow or to movement of current
-The unit of resistance is the ohm ()
-Factors affecting resistance
   -Area of cross section of the conductor
   -Length
   -Temperature
   -Material
         Ohm’s Law
-the amount of current is proportional to the
potential difference applied to the ends of
the wire and is inversely proportional to the
resistance of the wire



           V = IR
                    Power

-rate at which a load (resistor) uses energy
-Energy transformed per unit of time

P = VI              P = I2R
P = V2/R
Units =
      Watt
      Kilowatt hours (E = Pt)