Electri

Static ElectricityThe build upbuild up of an electric charge

on the surfacesurface of an object.The charge builds up but does not does not

flow.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 only the components on that branch the components on that branch will turn offwill turn off.

Conductors vs. InsulatorsConductorsConductors – material through

which electric current flows easilyeasily.

InsulatorsInsulators – materials through which electric current cannot cannot movemove.

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 resistanceThicknessThickness – the thicker the wire the

lower the resistanceLengthLength – shorter wire has lower

resistanceTemperatureTemperature – 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 “pressure”greater the force or “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 coilcurrent bearing coil of wire wrapped around an iron or steel iron or steel core.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.