1. Contact Points and Light Bulbs
Physics First
Unit 1 Electricity

2. Contact Points All electrical points have contact points
Contact points- allow electrical current to flow
Inside the device there is a pathway (without breaks) so current can flow

3. Contact Points
All devices must have at least 2 contact points (some have more)
One point allows current to flow in while the other allows current to flow out
Contact points must be separated by some insulator

4. Anatomy of a Light Bulb
3. filament wire- current passes through and creates heat which turns to light
4 and 5- contact wires that connect to filament
9 and 11- outside contact points insulated by 10
8- wire connected to inside contacts

5. Anatomy of a Light Bulb 1. Glass bulb- protector
2. Inside gas- does not allow the filament to burn out
6. Support wires- no electrical purpose
7. Stem- glass mount

6. Symbols
Resistor- (light bulb, motor, buzzer) device that a current can cross

7. Symbols
Wire
Battery

8. Symbols
When a switch is opened or closed we must show it in our circuit diagrams