1. Learning Objectives
To learn the difference between static and current electricity
To build a circuit

2. Current Electricity
Refers to the movement of electrons through a conductor in a controlled fashion

3. Static vs Current Electricity
Static Electricity
Current Electricity
Steady in a given direction
Type of electron movement
Random
Path of electrons
Unpredictable
Can be directed
Short
Long
Duration of flow
Can power appliances
Stationery objects
Usefulness

4. Electric Circuits
To make any electrical device operate a continuous flow of electrons is required
The continual flow of electrons is called an electric circuit
What do we need to complete a circuit?

5. 1. Energy Source As small as a battery…
as large as a generating station

6. 2. The Load
Any device which converts electrical energy to another form of energy
In other words, anything that runs on electricity

7. 3. Connecting Wires Joins all the parts of the circuit together
Allow the source and the load to be far apart
Made of good conducting material
Provide a controlled path for electrons

8. 4. The Switch Optional Controls electron flow
‘On’ = closed circuit and electrons flow
‘Off’ = open circuit and flow is stopped

9. Closed circuit – Switch is ‘on’

10. Open circuit – Switch is ‘off’

11. Circuit Symbols Sources of electrical energy: + - Single battery
+ -
Single battery
Three batteries

12. Electrical Conductor:
(always draw 90o corners, and straight lines)
Control Device: Open Switch
Closed Switch

13. Loads:

14. Loads, cont’d:
Ohmmeter

15. Why do we use circuit diagrams?
So this…….
Becomes this!

16. Series Circuits Electrons have only one path to follow
Loads are all connected one after the other (i.e. in series)
If any part of the circuit is broken, none of the loads will work
Ex: if one light bulb burns out, none will light up

18. How would you draw a circuit diagram for 3 lamps connected in series, with a switch and one electric cell?
Draw a circuit diagram with a three-cell battery in series with a switch and 2 lamps.

19. Parallel Circuits Electrons have two or more paths to follow
Loads are all connected by branches
One faulty load will not affect the others
Ex: if one light bulb burns out, the others will continue to work
In your home, parallel circuits separate smaller series circuits

21. How would you draw a circuit showing a two-cell battery with three lamps connected in parallel, and a switch for each lamp?
Draw a circuit diagram showing a two-cell battery, two lamps, and one motor. The loads are connected in parallel.

22. Practice!
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