2. What is a circuit? A set of connected electrical components that provide one or more complete paths for the movement of charges. A set of connected electrical components that provide one or more complete paths for the movement of charges. A complete path from one battery terminal to another = “closed circuit” A complete path from one battery terminal to another = “closed circuit” Any break in the path = “open circuit” Any break in the path = “open circuit”

3. Circuit diagrams Circuit/schematic diagrams are used to represent electric circuits. Circuit/schematic diagrams are used to represent electric circuits. Symbols include: Symbols include: Wire Battery Resistor Light Bulb Switch +-

4. Simple Circuit Diagram Simple circuit = power source, wire, and bulb

5. Types of Circuits Two types: Two types: 1. Series circuit - provides a single conducting path without junctions. - the current has only one loop to flow through - the current has only one loop to flow through - the amount of current is the same through every part - the amount of current is the same through every part

6. Series Circuits - Output devices that are connected in the same loop are in “series” - What happens when there is a break in the connection? BOTH LIGHTS GO OUT!!!

7. 2. Parallel Circuit - contains two or more branches for current to move through. - Individual parts can be turned off without affecting the entire circuit. Ex: electrical system in a house - Electrical energy enters your home at the circuit breaker or fuse box. - Electrical energy enters your home at the circuit breaker or fuse box. - Guards against overheating electric wires. - Guards against overheating electric wires. Types of Circuits

8. Parallel Circuit A B What happens when switch A breaks the connection? Switch B?