From Energy to From Energy to ElectricityElectricity

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Understanding How Understanding How Electricity WorksElectricity Works

Catherine WalkerAmerican Public University

What is energy?

Energy is the ability to do work.

In fact, whenever something moves, heats, cools, grows, changes or produces light or sound,

energy is involved.

Energy is the power to change things.

Static vs. Current

There are two kinds of electricity:

•Static electricity – Imbalance of positively and negatively

charged atoms. – Electrons jump from atom to atom, releasing

energy. – Two examples of static electricity are lightning

and rubbing your feet on the carpet and then touching a doorknob.

Static vs. Current

There are two kinds of electricity:

•Current electricity – Constant flow of electrons. – Two kinds of current electricity: direct current

(DC) and alternating current (AC). • Direct current: electricity the electrons move in one

direction. Batteries produce direct current. • Alternating current: electrons flow in both

directions. Power plants produce AC electric current.

Primary Sources of Energy

The Basics of Generating Electricity

How Electricity Travels

Electricity

Electricity is a secondary source of energy. That means that we must use other energy sources to make electricity.

What are the three primary energy sources

used in the U.S. to generate electricity?

California's Generation Mix (2008)

Electricity

In your home, electricity runs the lights, television, toaster, and more.

What else around your home requires

electricity to operate?

It’s easy to see what electricity does for us, but

how does electricity really work?

A Complete Electrical Circuit

For electricity to work, you need a complete circuit.

A complete a circuit is made up of three things:

1. A source of electrons.

2. Something to use the electrons.

3. A path for the electrons to move.

Current Electricity

1. A source of electrons.

2. Something to use the electrons.

3. A path for the electrons to use.

Can you detect the three things that make up a complete circuit?

A bit more about electrons

The wire in an electrical circuit is made of atoms. Atoms contain electrons.

Electrons move from one atom to another. When electrons move between atoms, a current of electricity is created.

Demonstration of how electrons move from atom to atom.

A Working Circuit

Building a CircuitLabel Your Diagram

Here is What We Will Build

Build an Electric Circuit

How Our Electric Circuit Compares to Your House

Do you see two complete circuits?

An Electrical Circuit in Your Home

Conductors and Insulators

Conductors

These are materials in which it is easy to get electrons to move and

provide a flow of electric current.

• Paperclip• Piece of copper• A bolt

Insulators

These are materials in which it is difficult

to get current

to flow.• Paper• Plastic• Styrofoam

What do conductors have in common?