1. Series and Parallel circuits
Energy and Change
Series and Parallel circuits
CAPS
Sutherland High School
Platinum Natural Science
Grade 8
TB pg. 153

2. QUICK REVISION What is a circuit? (pg. 136)
What is the “energy source” in a circuit?(pg. 136)
What materials are conducting wires usually made from? (pg. 136)
Explain the role of a fuse in a circuit? (pg. 149)

3. QUICK REVISION
Why is a light bulb also called a resistor in a circuit?(pg. 136)
Name the components represented by these symbols:

4. Components in a circuit can be connected in 2 different ways:
QUICK REVISION
Components in a circuit can be connected in 2 different ways:
Series connection
and
Parallel connection 1. 2.
TB pg. 153

5. Series circuits Components are connected one after the other.
There is only one pathway for the current to flow through.
TB pg. 154

6. Series circuits
The light bulbs act as resistors in the circuit. The more resistors there are, the slower the flow of electricity will be.
Think of a hosepipe.
TB pg. 154

7. Series circuits
The current is the same everywhere in the circuit, but every time a resistor is added in series, the overall current in the circuit decreases.
You can see the effect of the reduced current by the reduced brightness of the light bulbs.
TB pg. 154

8. Materials that conduct electricity
Conductors
Materials that allow electric current to flow through them.
Examples:
Copper, Steel, Silver, Gold
TB pg. 155

9. Materials that conduct electricity
insulators
Materials that do not allow electric current to flow through them. (or allow very little)
Examples:
Plastic, rubber, glass, wood
TB pg. 155

10. Parallel circuits
Provides two or more pathways for the current passing through it.
Think of the current as cars and the parallel circuit as roads.
Parallel circuit
TB pg. 157

11. Parallel circuits
The overall current increases as more resistors are added in parallel.
If one resistor doesn’t work, then the others will still continue to work.
Parallel circuit
TB pg. 157

12. Output devices
Component in a circuit that transforms the potential energy in a cell / electrical energy into other forms of energy such as heat, sound or light.
TB pg. 159

13. Output devices ?
TB pg. 159

14. Electrical Light Output devices Examples Light bulb/L.E.D TB pg. 159
Input energy
Examples ↓
Light bulb/L.E.D
Electrical
Output energy ↓
Light
TB pg. 159

15. Electrical Sound Output devices Examples Beeper/Buzzer TB pg. 159
Input energy
Examples ↓
Beeper/Buzzer
Electrical
Output energy ↓
Sound
TB pg. 159

16. Electrical Kinetic Output devices Examples Motor TB pg. 159
Input energy
Examples ↓
Motor
Electrical
Output energy ↓
Kinetic
TB pg. 159

17. Homework
Topic 9 revision
Pg. 162
Classwork
Activity 7 pg. 159