1. Define insulator and conductor. Write 3 examples of each.
Bell ringer
Define insulator and conductor. Write 3 examples of each.

2. Standards and Objectives
GLE Describe how simple circuits are associated with the transfer of electrical energy.
Identify how simple circuits are associated with the transfer of electrical energy when heat, light, sound, and chemical changes are produced.

3. ELECTRICAL CIRCUITS

4. The CELL
The cell stores chemical energy and transfers it to electrical energy when a circuit is connected.
When two or more cells are connected together we call this a Battery.
The cells chemical energy is used up pushing a current round a circuit.

5. A SIMPLE ELECTRICAL CIRCUIT
GLOBE
Watch what happens when I click on the light switch to open and close the circuit.
WIRE
BATTERY
SWITCH
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6. Current: the actual “substance” that is flowing through the wires of the circuit (electrons!)

7. simple circuits
Here is a simple electric circuit. It has a cell, a lamp and a switch.
wires
cell
lamp
switch
To make the circuit, these components are connected together with metal connecting wires.

8. simple circuits
When the switch is closed, the lamp lights up. This is because there is a continuous path of metal for the electric current to flow around.
If there were any breaks in the circuit, the current could not flow.

9. circuit diagram
Scientists usually draw electric circuits using symbols;
cell
lamp
switch
wires

10. COMMON ELECTRICAL SYMBOLS BATTERY x1 BATTERIES x2 BATTERIES x3 GLOBE
WIRE
SWITCH
CLOSED
(ON)
SWITCH
OPEN
(OFF)
WIRES CROSSING
BUT NOT CONNECTED

11. Simple Circuits Series circuit Parallel circuit All in a row
1 path for electricity
1 light goes out and the circuit is broken
Parallel circuit
Many paths for electricity
1 light goes out and the others stay on

12. SERIES PARALLEL DIFFERENCES BETWEEN SERIES & PARALLEL CIRCUITS
If one globe burns out
or is removed, all globes
will stop working.
If one globe burns out
or is removed, all other globes will continue working.
DIFFERENCES BETWEEN SERIES & PARALLEL CIRCUITS
The voltage is shared between each globe, resulting in reduced
brightness.
Each globe receives the full voltage of the source, resulting in all globes burning at the same brightness regardless of the number of globes.
Serial circuits are cheap and easy to construct.
Parallel circuits require more effort to construct.

13. How do currents travel?
Alternating Current-Travels in two directions. Example- A house
Direct Current-Travels in one direction. Example- A battery

14. Summarizer Number your composition book from 1-4.
Make sure to leave plenty of space to write your answers.

15. The voltage decreases because the current is decreased
The circuit is no longer complete, therefore current can not flow
The voltage decreases because the current is decreased
and the resistance increases.

16. The current remains the same
The current remains the same. The total resistance drops in a parallel circuit as more bulbs are added
The current increases.