1. Current electricity

2. Energy source: Electricity
Recall where charge comes from in the atom
Protons: positive charge
Neutrons: no charge, neutral
Electrons: negative charge
Only electrons are free to move!
Law of electric charges:
unlike charges attract
like charges repel
Neutral objects are
attracted to charged objects

3. Activity: Like and Unlike Charges
Examine the labeling on a dry cell
A. which end produces electrons? Which end has a deficit? Explain.
B. Predict what will happen if you connected the ends (terminals) with a wire. Use the law of charges to support your answer.
C. Test your prediction, but for no longer than 5 seconds!
*this creates a short circuit that rapidly drains the cell of energy.
What did you observe?

4. Answers

5. What is the difference between Static electricity and Current Electricity?

6. Types of Electric Charge : Static
Static charge is charge at rest;
NOT moving
Objects rub against one another
(friction) and transfer charge
(creates static electricity)
Van de Graff generator
As belt moves rapidly over rollers,
the contact results in transfer of charge
onto the metal dome, which can be
transferred to objects
- Sparks when the build up is “discharged”

7. Types of Electric Charge : CURRENT
Current electricity refers to electric charges flowing in a circuit through a conductor.
What moves?
Electrons!

8. Current Electricity
This is electricity that flows from one place to another
Many examples of current electricity are easy to spot because they use cords/wires plugged into an outlet in the wall; other devices use batteries

9. Challenge MIT - Lighting a lightbulb
Can you light a light bulb with one wire, one light bulb and 1 battery?

10. Electric Circuits
A complete pathway that allows electrons to flow is called an electric circuit. Electrons flow through devices (loads) in the circuit that convert electricity to other forms of energy.

11. ACTIVITY: Circuit Puzzles

12. Answers

13. Activity: Conductor or Insulator?

14. Answers

15. What types of materials allow electrons to flow?
These are called conductors
Metals are the best conductors of electricity (electrons allowed to travel freely)
Materials that prevent electricity (electrons) flowing freely are called insulators

16. Parts of An Electric Circuit
There are four important components to a circuit:
1. Energy Source
Chemicals – ionic compounds in solution – ions float freely and the electrons are allowed to move through the solution to complete a circuit
Electric cell - (we mistakenly call it a battery, a battery is actually 2 or more cells combined).
In houses - power comes from an outside source. (In BC = Hydro power)

17. Electric Cell Diagram: A battery is 2 or more electric cells
2 Types of Batteries:
Primary – not rechargeable – can’t reverse the reactions
Secondary - rechargeable

18. Parts of an Electric circuit
2. Load - converts electrical energy into another form of energy (light, heat, sound etc.)
Without a load, connected batteries would
burn out quickly!
Examples of a load:
Dishwasher, stove, microwave, stereo, tv, light- bulb
Motor
Resistor
Light bulb

19. Parts of an Electric circuit
3. Conductor – wire where the electrons (current) flows,
Used to connect and complete the circuit
4. Switches – to open (on) or close (off)
your circuit
Other components in a circuit:
Meters – to measure amount of
Voltage
Current

20. Electrical Circuit
explanation

21. Draw a picture of a circuit with a cell, a bulb and connecting wires

22. Circuit diagram
A schematic that simplifies the information

23. Circuit diagram - Symbols
motor
fuse
resistor
ammeter

24. Circuit Diagrams 1 cell, 1 switch, 1 light bulb
You try: 2 cells, 1 motor, 1 light bulb controlled by one switch.
How would you have to arrange them if you want to control them by separate switches?

25. If we wanted to connect two batteries, how would we do it?

26. Series vs. Parallel
Arrangement of Cells

27. Circuits in series

28. Answers

29. Series vs. Parallel Arrangement of loads (ex. Light bulbs) Series –
There is only a single pathway for current to flow
Parallel –
Current splits up between the different pathways

30. Series Vs. Parallel Circuits
Types of Circuits

31. PRACTICE Drawing Electric Circuits Sheet
Ammeters are drawn directly on the wire, on the same path as a light bulb
Voltmeters are drawn across a load (device), if there is one in the circuit

32. Permit #2
Circuits in Series and Parallel