1. Current, Resistance, and Simple Circuits

2.  A capacitor is a device used to store electrical energy.  There are two different ways to arrange circuit components:  Series  Current is constant, voltage varies  Parallel  Current varies, voltage is constant Review

3.  Current – The flow of electric charges through a piece of material.  Throughout these notes, we are going to compare circuits to water.  Current is like the speed that water is flowing. Rapids would represent a large current.  Current is the rate at which charges flow through a specific area. Current

4. # of Charges Duration (Time)

5.  Resistance – A charged particle’s resistance to a change in motion in response to an external force.  Resistance is like the widening or shrinking of a pipe to change the rate of flow of water through a pipe.  Resistors are used to control the current in different parts of a circuit. Resistance

6.  Current, Resistance, and Voltage all affect each other.  Voltage is the push. Current is the flow. Resistance is the slowing down of current.  Ohm's Law Demo Ohm's Law Demo Ohm’s Law

7. Voltage Current Resistance

8. Resistivity Length of Material Cross-Sectional Area Temperature Temperature Coefficient of Resistivity

9. Electrical Power

10.  Direct Current Circuit (DC) – A circuit that has a current that is constant in magnitude and direction.  Alternating Current Circuit (AC) – A circuit that has current that is changing in magnitude and direction.  Electromotive Force – The maximum possible voltage that a battery can provide (Symbol: ε) Direct vs. Alternating Current

11.  Remember the symbols from last week:  Wire  Battery  Capacitor  Switch  And two new ones:  Resistor  Light Bulb Circuit Design

12. Resistors in Series R1R1 R2R2 R3R3 Battery

13. Resistors in Parallel R1R1 R2R2 R3R3 Battery

14.  Let’s take a look at why Current and Voltage change depending on the type of circuit we have.  Circuit Construction Circuit Construction

15.  Calculate the current and voltage delivered to each resistor in the circuit shown below. Practice Problem 18 Volts 4 Ohms 2 Ohms 3 Ohms 1 Ohm