Static ElectricityThe build upbuild up of an electric charge on the surfacesurface of an object.

The charge builds up but does does not flow.not flow.

Static electricity is potential potential energyenergy. It does notnot move. It is storedstored.

Electricity that moves…CurrentCurrent: The flow of electrons from one place to another.

Measured in amperesamperes (amps)KineticKinetic energy

There are 2 types of currents:Direct Current (DC)Direct Current (DC) – Where electrons flow in the samesame direction in a wire.

There are 2 types of currents:Alternating Current (AC)Alternating Current (AC) – electrons flow in differentdifferent directions in a wire

There are 2 types of circuits:Series CircuitSeries Circuit: the components are lined up along oneone path. If the circuit is broken, all all components turn off.

There are 2 types of circuits:Parallel CircuitParallel Circuit – there are severalseveral branching paths to the components. If the circuit is broken at any one branch, only the components on that only the components on that branch will turn offbranch will turn off.

Conductors vs. InsulatorsConductorsConductors – material through which electric current flows easilyeasily.

InsulatorsInsulators – materials through which electric current cannot movecannot move.

ExamplesConductorsConductors:

MetalWater

InsulatorsInsulators:StyrofoamRubberPlasticPaper

What is Resistance?The oppositionopposition to the flow of an electric current, producing heatheat.

The greatergreater the resistance, the lessless current gets through.

GoodGood conductors have lowlow resistance.

Measured in ohms.ohms.

What Influences Resistance?Material of wireMaterial of wire – aluminum and copper have low resistance

ThicknessThickness – the thicker the wire the lower the resistance

LengthLength – shorter wire has lower resistance

TemperatureTemperature – lower temperature has lower resistance

What is Voltage?The measure of energymeasure of energy given to the charge flowing in a circuit.

The greatergreater the voltage, the greater the force or greater the force or “pressure”“pressure” that drives the charge through the circuit.

Difference b/t Volts and AmpsExample – you could say that…AmpsAmps measure how muchhow much water comes out of a hose.

VoltsVolts measure how hardhow hard the water comes out of a hose.

Ohm’s Law

Resistance = Voltage / Current

Ohms = Volts / Amps

Practice with Ohm’s LawOhmsOhms VoltsVolts AmpsAmps

44 100100 2525

1515 150150 1010

22 3030 1515

99 4545 55

66 4848 88

What is an electromagnet?ElectromagnetElectromagnet – a magnet made from a current bearing current bearing coilcoil of wire wrapped around an iron or steel core.iron or steel core.

What is a generator?GeneratorGenerator – a machine that changes mechanicalmechanical energy to electricalelectrical energy

Usually use movingmoving magnets to create currentscurrents in coils of wire.

What is a motor?MotorMotor – a device that changes electrical electrical energy to mechanical mechanical energy that can do workwork.