Download 13.1 CIRCUITS AND CIRCUIT DIAGRAMS

13.1 CIRCUITS AND CIRCUIT DIAGRAMS
Drawing Schematic Circuit Diagrams
When drawing circuit diagrams, we use specific symbols.
Sources:
Cell
Conductor
Connecting Wire
Battery with Three Cells
Loads:
Light Bulb or lamp
Resistor
Motor
Control Devices:
Open Switch
Closed Switch
Fuse
Measurement Devices:
Voltmeter
Ammeter
Ohmmeter
Draw circuits containing the following components:
Example 1:
One cell
One switch that controls the whole circuit
One light bulb with two motors
An ammeter
Which way do the electrons flow?
Example 2:
2 cell battery
2 light bulbs
Voltmeter that measures the first light bulb
Series and Parallel Circuits
SERIES CIRCUIT
A series circuit is a circuit in which electrons flow in only one path (a continuous loop) and
pass through all components of the circuit.
In a series circuit, the voltage decreases as you increase the number of loads.
In a series circuit, if you remove one load, the circuit becomes incomplete (open)
The charges pass through every load before returning to the electrical source to be reenergized again.
Example 3: Draw a circuit containing the following components in series:
One dry cell
One switch that controls the whole circuit
Three light bulbs in series
PARALLEL CIRCUIT
A parallel circuit is a circuit in which electrons flow in multiple paths.
In a parallel circuit, the loads are on at least two different branches. The electrons that leave
the source are split between the loads.
In a parallel circuit, if you remove one load, there are still other paths for electrons to flow.
In a parallel circuit, as you increase the number of loads, the current at the battery will increase
to meet the demand of multiple paths of current. Overall, the current across each load is
smaller than at the battery.
Example 4: Draw a circuit containing the following components:
One dry cell
One switch that controls the whole circuit
Three light bulbs in parallel
HOMEWORK: Read Page 551-554 and do questions #1-7 on Page 554