1. Warm-Up 12/19/13
Draw a 3 frame cartoon strip that shows the series of events that may cause you to receive a shock from a metal door knob on a dry winter day.

2. 20.2 Electric Current and Ohm’s Law
Thursday 12/19/13

3. Electric Current A continuous flow of electric charge
Measured in Amperes/Amps (A)
There are two main types:
Direct Current (DC)
Alternating Current (AC)

4. DC AC Charge flows only in one direction
Example: flashlight or battery operated device
Flow of electrical charge that changes direction
Example: electricity in home and school

5. Voltage Also known as the “potential difference”
The difference in electrical potential energy between two places in an electric field
CHARGE FLOWS FROM AREAS OF HIGH TO LOW CHARGE
Sources of voltage: batteries, solar cells, generators

7. Conductors & Insulators
Different types of materials are better at supporting an electric current
Conductors: charge can flow easily, like in metal wires
Insulators: charge can’t flow
easily, like through plastic or rubber

8. Resistance
Measures the opposition or difficulty of charge flow in a material
Unit is Ohms
Low resistance materials are
THIN, SHORT, AND COLD
High resistance materials are
THICK, LONG, AND HOT

10. Voltage (Volts) = Current(Amps)x Resistance (Ohms)
Ohm’s Law
Shows the relationship between voltage, current, and resistance.
You can increase voltage by increasing current or resistance
V = I x R
Voltage (Volts) = Current(Amps)x Resistance (Ohms)

11. Your Job
Complete the Ohm’s Law practice problems.