2.  Measurement of difference in potential energy between 2 locations in a circuit.  Also called potential difference  Measured in volts (V)  Drives the current through a circuit using the attraction or repulsion of charges due to the electromagnetic force  Voltage, current and resistance in a circuit could be represented by a hose connected to a water tank.

3.  Diagram from page 398 in journal  Water= electrical current  Tank= battery  Water pressure= voltage  Valve= resistance  Open valve= low resistance  Closed valve= high resistance

4.  In many DC circuits, voltage is generated by battery  Smaller objects can use smaller voltage (smaller battery)  Larger objects need more voltage (larger battery)  A car battery is made of 6 smaller batteries, but you couldn’t replace it with 10 flashlight batteries and get the current needed to start the car.

5.  In a circuit diagram, a battery is represented by 2 different sized parallel lines that are perpendicular to the wires they are connected to. The shorter line represents the (-) terminal and the longer is the (+) terminal.  The current leaves the (+) terminal, travels through the circuit, and reenters the battery through the (-) terminal.  Voltage of the battery is equal to the potential difference between the 2 terminals.

6.  Another voltage source for a circuit is a power supply.  The amount of voltage supplied can be varied by turning a dial providing a way to monitor and control the amount of supplied voltage.