190 likes | 324 Views
Electricity. Warm Up. Define electricity? How do we measure electricity? What is the difference between AC and DC power? How does battery work?. Flow of electrons. When a circuit is complete, electrons flow from the negative to positive end, producing a current.
E N D
Warm Up • Define electricity? • How do we measure electricity? • What is the difference between AC and DC power? • How does battery work?
When a circuit is complete, electrons flow from the negative to positive end, producing a current
Voltage - The potential difference between two test points resulting from the distribution of charge in the circuit, usually measured in volts • Current - number of electrons flowing past a specified point, usually measured in Amps.
Power - energy given in a certain amount of time, usually measured in watts. • Volt x Amps = Watts • Household usage measure in Kilowatts
Conductors - Materials which contain movable charges that can flow with minimal resistance (metals) - gold - copper
Insulators - Materials with few or no movable charges, or with charges which flow with extremely high resistance (rubber)
Resistance – limits the flow of current. Measure in Ohms. Control the # of electron flow.
Resistance = Voltage / Current • R = V / I
AC vs DC • AC – Alternating current - electric charge go in both directions • DC – Direct current - electric charge go in 1 direction - battery
Direct Current http://www.howstuffworks.com/battery.htm 4.5-volt, D, C, AA, AAA, 9-volt, SR41/AG3, SR44/AG13