Day 2: Day 2: Parts of a Parts of a

CircuitCircuit

Simple CircuitsSimple Circuits An An electric circuitelectric circuit is the is the

path that an electric path that an electric currentcurrent follows follows

Current is Current is flowingflowing charges, like cars on a charges, like cars on a highway – THIS IS highway – THIS IS DIFFERENT FROM DIFFERENT FROM STATIC STATIC ELECTRICITY!!!ELECTRICITY!!!

Circuit DiagramsCircuit Diagrams

BatteryBattery

SwitchSwitch

Light Light bulbbulb

WireWire

All electric circuits have All electric circuits have three parts:three parts:

Source of electric Source of electric energy (battery or energy (battery or wall outlet)wall outlet)

WiresWiresDevice that uses Device that uses

the energy (light the energy (light bulb, stereo, etc.)bulb, stereo, etc.)

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Circuits Circuits flow flow in a in a

circular circular path path from from

positive positive to to

negativenegative

Open or Closed?Open or Closed?

In order for electricity to move In order for electricity to move through a circuit it must be through a circuit it must be closedclosed

If a circuit is open then the If a circuit is open then the electricity cannot flowelectricity cannot flow

SwitchesSwitches are objects that are are objects that are used to determine whether a used to determine whether a circuit will be closed or circuit will be closed or openedopened

http://phet.colorado.edu/new/simulations/sims.php?sim=

Circuit_Construction_Kit_DC_Only

openopen

There are two types of circuits…There are two types of circuits…

SeriesSeries

ParallelParallel

Types of CircuitsTypes of Circuits

                                                                                                           

What is the difference between the wiring?

Series CircuitsSeries Circuits

This is the This is the simplestsimplest typetype ofof circuitcircuit

Series CircuitsSeries CircuitsThe electric charges can The electric charges can follow follow only one pathonly one path through through the wires of the circuitthe wires of the circuitIf one part goes out, they all If one part goes out, they all go out.go out.

Ex. – Old-style Christmas Ex. – Old-style Christmas lights are lights are wired this waywired this way

Series CircuitsSeries Circuits

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If this light bulb does not turn on,If this light bulb does not turn on,

neither light neither light bulb will bulb will turn on.turn on.

The circuit is broken and the current can’t flow to this bulb here.

Burned out light bulb

Parallel CircuitsParallel Circuits

The electric current can follow The electric current can follow more than onemore than one path (branch) path (branch)

Parallel CircuitsParallel Circuits

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The current divides because it has The current divides because it has more than one path to flow.more than one path to flow.

Even though the path is stopped, the other light turns on because its circuit is not broken.

Burned out light bulb

Parallel ContinuedParallel ContinuedSo would So would seriesseries or or parallelparallel

be better to wire a be better to wire a househouse??

ParallelParallel because if one light because if one light is missing or not working, is missing or not working, the other lights have the other lights have alternate paths to follow and alternate paths to follow and will STAY LIT!will STAY LIT!

Building CircuitsBuilding Circuits

Materials:Materials: WireWire CellCell BulbsBulbs switchswitch

Build a Build a series circuit series circuit with a switch to control with a switch to control the light bulbthe light bulb

Build a Build a parallel circuit parallel circuit with 2 light bulbs and a with 2 light bulbs and a switch that controls one switch that controls one light bulb onlylight bulb only