1. Electricity Within a Circuit
Topic 2
Electricity Within a Circuit

2. 1. When charged objects are brought close to uncharged objects, this occurs… A. separation B. attraction C. neutralization D. atomization 2. The laws of electric charges include all of the following, EXCEPT… A. opposite charges attract each other B. charged objects attract neutral objects C. similar (like) charges repel each other D. opposite charges repell each other 3. Materials can be conductors, semiconductors, superconductors, or insulators. Which of the following materials would make a good insulator? A. aluminum B. human body C. silicon D. porcelain

3. Electric vocabulary

4. Static Current Electricity Charges are stationary
Electricity occurs in 2 different forms.
Static
Charges are stationary
e.g. Brush your hair, Wool socks in drier
Current
Flows around circuit
e.g. turn on light, computer
Lightning is static, particles in cloud bang each other build up +ve at top of cloud, -ve at bottom, -ve causes +ve on ground, centres around high object, when charges meet discharge as electricity
Lightning kills over 100 each year more than tornado/ hurricane
Lightning hotter than surface of sun
How do you react in storm

5. Static Electricity Review
Occurs with materials which are insulators
Rubbing adds or removes electrons
Object becomes charged
Like objects repel, unlike attract
Rubbing insulator removes or adds electrons so object is charged creates electrical force field so other objects are attracted or repelled
Rub feet on carpet and touch door handle
Brush hair stands up
Socks stick to nylon in tumble drier
Try expt charge plastic rod pick up paper, hair, bend water, balloon hair stand up, stick to wall, try against lightbulb
Van der graff
Video

6. Current Electricity
Static charges do not work very well for operating electrical devices
Electrical current is produced as charges move in a continuous flow
An electrical current flows until it is used up or disconnected
Think of it like water flowing until it is dammed or its source drives up

7. Electric Eels http://www.youtube.com/watch?v=a3sviTa8hZw
World’s deadliest: Six-Foot Electric Eel

8. How do we move electricity to its destination?
Answer: CONDUCTORS Conductors are materials that electrical energy can move easily through.

9. Circuits
A circuit is a path that controls the flow of electricity (just like pipes and taps in a water system control the flow of water).
In most pathways, electricity flows along solid metal wires, but circuits can also include gases, other fluids, etc.

11. The most complex circuits are made up of FOUR basic elements
Source – The source of electric energy
Conductor – The wire through which current flows
Load – Items along the circuit that convert electricity into other forms of energy (ex. Light bulbs, motors)
Control – A switch or device that can turn the circuit or devices along it on or off.

13. Series circuit Has a single loop for electrons to travel round
Components are connected one after another
Current has to travel through all components
Current is the same at all points
Voltage is shared between components
EXPT make buzzer game groups attempt each others

14. Parallel circuit Has two or more paths for electrons to flow down
Current is shared between the branches
Sum of the current in each branch = total current
Voltage loss is the same across all components
H/O drawing parallel circuits
ARB H/O what wrong with circuit?

15. A battery describes two or more cells connected together.
A single “battery” is called a cell.
-D. C. AA. AAA are incorrectly called batteries – they should actually be called cells
-Car batteries are correctly called batteries because they contain more than one cell.

16. Practice drawing some circuits