ELECTRICITY

What would life be like without electricity?

Maybe like this…

Or this…

You couldn’t do this…

Or this…

And our cities wouldn’t look like this…

Why is electricity important to us?

Electricity provides us with … Heat Light Sound Motion

So where does this “magic” electricity you use every day come

from?

Abracadabra!

Electron movement!

SO, WHY DO ELECTRONS MOVE?

Let’s Review First

Electrons are the only particle of an atom that can move from one atom to another

Electrons have a negative charge, protons have a positive charge

Everything in environment carries either a positive, negative, or neutral charge Add electrons and an atom becomes more

negatively charged Take away electrons and an atom becomes

more positively charged Charged atoms are called IONS

Movement of Electricity

Electrons will move when they have a “push” of energy from A Battery A Power Plant or other Energy Source

The energy is then transferred through a conductive material, usually wires or cables, this flow of electrons (negative charges) is called an electrical current

Electrical Currents

Electrons flow from areas of negative charge to areas with a positive charge in a current

If the current runs in a circular path from the battery or power source it is called a circuit

What materials can carry electrical currents?

Conductors-electrons flow easily through them Examples: metals such as copper, gold, silver

Semi-Conductors-electrons move less easily through them Examples: aluminum, zinc, silicon

Insulators-electrons DO NOT flow easily through them Examples: rubber, paper, plastic, wood

Electrons Have Mass Ever notice that your phone becomes

warm when you are using it, or a plug in an outlet feels warm when you remove it?

This is because electrons have MASS, it is extremely small, but enough so that when electrons are flowing some of them bump into each other, creating HEAT

WARNING: The safest way to charge electronics is to turn them off while they are charging, otherwise you could start a FIRE!

More Electric Safety

Don’t over connect outlets!

State Farm Holiday Safety Video

How do power stations make energy to create electricity?

Usually burn fuel which heats water and creates steam

Steam turns turbine which turns a rod with a magnet

Causes electrons to flow around a wire wrapped around the magnet

Electrons then carried by wires throughout the region

How is Electricity Transported?

How do batteries work?

Batteries use energy stored in chemicals to allow electric current to flow

Once the energy is used up, the current can no longer flow

The current will flow from the negative end of the battery to the positive endNegative end-ANODEPositive end-CATHODE

Static Electricity Called “non-moving” electricity Created when there is a build up of

electrons on one object and they try to neutralize with another positively charged object

The charge “jumps” from one object to the other

Coulomb’s Law

3 parts:1. Any two charged objects will create a force

on each other2. Opposite charges will produce an attractive

force (such as N and S pole of magnet)3. Similar charges will produce a repulsive force

(such as N and N side of magnet)

Electric Field

Electric Field - region in space where electric forces act on charges

Lightning over Icelandic Volcano 2010

Lightning

Big static electric sparks occur when opposite charges between clouds or between the clouds and the ground try to neutralize

Can happen from sky to ground or ground to sky

Video

Lightning Safety Tips

Avoid water Avoid high ground Avoid open spaces Avoid metal objects Electricity will follow shortest path to the

ground, make sure that isn’t through YOU!

If in an open area, lay flat on the ground If you are in a car, stay in it, you are

SAFE, anyone know why?

Faraday Cages

Metallic enclosures that prevent the entry or escape of an electromagnetic field

A CAR is basically a faraday cage! Electricity will travel around metal shell of the

car and into the ground and will not go through it

Sweet Home Faraday Suit Video

ALTERNATING CURRENT & DIRECT CURRENT

Direct Current

Flow of charge always in one direction Battery charged objects

Alternating Current

Flow of charge back and forth, changing its direction many times in one second. Plugs and outlets / household

Is AC or DC better?

Advantages of Alternating Current: Voltage can be raised or lowered More efficient over long distances

How is Electricity Measured?

Volts-measure of the force or pressure under which electricity flows

Amps-measure of the flow rate of electrons or how much current moves through the wire in 1 second

Watt-measure of electrical power created Water Faucet analogy

Faucet turned on all the way-high voltage and amps

Faucet barely turned on dripping water-low voltage and amps

Ohm’s Law

Watts=Volts x Amps or W=V x A