The Physics of Electricity &

Magnetism

I wonder what would happen if I put these

in my ears?

I am not too bright, but I will be soon!

Since the beginning, Humans have been fascinated by electricity, but only in the last few

hundred years have we really understood what it is and how to use it.

Today without electricity

what would happen?

Electricity affects everything in our

lives!

But what is it, and where does it come

from?

SummaryElectricity is a build up of

negatively charged particles

called Electrons.When they are still, they are

called Static Electricity. When they are moving, they are

Electrical Current.

To understand electricity we must understand

magnetism. To understand magnetism, we must understand the

ATOM.

The Atom• Atoms are made of parts • The core or center is the nucleus

–The nucleus is made of positively charged protons and neutral neutrons.

• Around the nucleus are negatively charged electrons

Electrons – duh – are the key to electricity. After all, where do you think electricity gets it name?

You should remember from 1st, 2nd, 3rd, and 4th grade, that things that have the same

magnetic charge repel each other or push each other away.

You should remember from 1st, 2nd, 3rd, and 4th grade, that things that have the same

magnetic charge repel each other or push each other away.

You should also remember from 1st, 2nd, 3rd, and 4th grade, that things that have different or opposite magnetic charges attract each

other or pull each other closer.

You should also remember from 1st, 2nd, 3rd, and 4th grade, that things that have different or opposite magnetic charges attract each

other or pull each other closer.

The atoms of some elements are special.

Those with only one or two electrons in the outer shell, like

copper, are special.

Copper Atom with its KEY electron circled.

This electron is loosely held and can be pushed or pulled onto other atoms creating a static electric charge.

The movable electron makes this atom negatively charged.

e

Extra Electron pushed from the neighboring copper atom.

What do you think can push or pull the electron?

That one electron is the key to electricity.

• In the 1800s, British scientist, Michael Faraday, discovered that if you move a magnet over a copper wire, the magnet will push the “special” electron in the copper and move it down the wire creating an electrical current.

By moving a magnet along copper wire, you can make the movable

electron move down the wire creating electric current.

For electricity to do work, it must travel in a circuit from an electricity source to the object that will do the work, back to the source or to ground

For electricity to work, it must be able to flow

from the negative pole on the battery, through whatever we want the electricity to run, back to the positive (neutral) pole on the battery or into the ground (which

is also generally positively charged.)

Negative pole

Positive pole

--

+

- -- The electron MUST be

able to make a complete

loop – a circuit.

+

- --If there is a break in the

loop ANYWHERE, the electron

gets stuck – it becomes

static.