1. Electric Circuits
Unit 10
Section 4

2. I. Electric Circuits
An electric circuit is a closed path through which electric charges flow.
A switch is used to open and close a circuit.
When a switch is closed, two pieces of conducting material touch, which allows electric charges to flow.
When a switch is open, the gap between the two pieces of conducting material prevents electric charges from flowing.

3. An example of a circuit. 1. Load 3 Major Parts of a Circuit
2. Electric current
(energy path)
3. Energy source

4. II. Parts of a Circuit There are three parts to a circuit: 1. load
2. electric current (energy path)
3. energy source
b. Load: What you are turning on, such as a light bulb or radio. They change electrical energy into other forms, such as sound.
Electric Current: The energy path (wires), which is what the electrons (energy) travels through.
Energy Source: places the electrons (energy) comes from.
1. For example: Batteries, photocells or generators.

5. III. Series Circuits
A circuit in which all parts are connected in a single loop.
There is only one path for the charges to flow through.
Label the 3 parts

6. IV. Uses for Series Circuits
Series circuits are often used in decorative lights.
If one of the lights goes out, they all go out because they are all on the same current.
You would not want to wire your home in a series circuit because if the lights went out in one room, the power would go out in all rooms.

7. V. Parallel Circuits A circuit in which parts are joined in branches.
There is more than one path for the charges to flow through. If one current stops working, the others will still work.

8. VI. Uses for Parallel Circuits
Your home is wired in a parallel circuit, each room having its own branch.
That way, if one light goes out, everything else in your house will keep working.
What kind of electric current, does your home use?
alternating current

9. VII. Ways that Electricity Stops
Fuses: have thin strips of metal on them.
i. If a current is too high, the metal will melt, which will stop the flow of electricity.
Circuit Breakers: switches that automatically open if the current is too high.
i. The open switch prevents any more electricity from flowing.

10. VIII. Electrical Safety Tips
Make sure insulation (rubber) on cords is not worn.
Do not overload circuits.
Do not use electrical devices while you are wet or in water.
Never put objects other than a plug into an electrical outlet.

11. Be Safe Around Electricity...or Else!

13. Quickie Quiz
True or false: When a switch on a circuit is open, the circuit will stop working.

14. Quickie Quiz
TRUE: When a switch on a circuit is open, the circuit will stop working.

15. Quickie Quiz
2. Which type of circuit has more than one path for the energy to flow through?
Series
Fuse
Parallel
None of the above

16. Quickie Quiz
2. Which type of circuit has more than one path for the energy to flow through?
Series
Fuse
Parallel
None of the above

17. Quickie Quiz
3. Which of the following helps to prevent electrical accidents by stopping the flow of electricity?
series circuit
fuse
parallel circuit
circuit breaker

18. Quickie Quiz
3. Which of the following helps to prevent electrical accidents by stopping the flow of electricity?
series circuit
parallel circuit
circuit breaker

19. Quickie Quiz 4. Which is NOT a way to stay safe around electricity?
Overload outlets.
Don’t use electricity while wet or in the water.
Make sure insulation on cords is not worn.
None of the above.

20. Quickie Quiz 4. Which is NOT a way to stay safe around electricity?
Overload outlets.
Don’t use electricity while wet or in the water.
Make sure insulation on cords is not worn.
None of the above.

21. Series or Parallel?

22. Series

23. Quickie Quiz
6. Which part of a circuit changes electrical energy into another form of energy?
switch
wire
load
energy source

24. Quickie Quiz
6. Which part of a circuit changes electrical energy into another form of energy?
Switch
Wire
Load
Energy source