The Energy Story

Energy Is Born

Energy Types

  Exercise 1
  Exercise 2
  The Ten Types
  - Kinetic
  - Gravitational
  - Spring
  - Electrical
  - Magnetic
  - Mechanical
  - Heat
  - Nuclear
  - Light
  - Chemical
  Crossword
  Energy Game

Energy Changes

Energy Generation

The Energy Problem

The Energy Solution

Secret Lives Title - The Energy Story

agif - compass
The Ten Types
Magnetic Energy

Magnetic and electrical energy are closely related to one another. When electrons move through a wire, a magnetic field is created around the wire. If the wire carrying the electrons is wound around a a metal bar of iron the iron will become magnetic and is called an electromagnet. The magnetic energy generated can be used to attract other metal parts and is used in devices like the magnetic hoists used to lift old cars into the car compactor.
electromagnet graphic
 

spinning electron graphic
Certain materials, mainly metals such as iron, nickel, and cobalt, can be permanently turned into magnets. This occurs when groups of atoms in the metal have their electrons all spinning in the same direction causing them to become little electromagnets. We have seen and used magnets to hold papers on refrigerators as one example and compasses to help us find our way.
 

The earth itself generates a magnetic field. This is caused by the rotation of the earth and the fact that the earth has a mainly liquid metallic core. This magnetic field helps protect us from being bombarded by particles and radiation from space. Many planets and stars also have magnetic fields.
 

Electromagnets can be designed to do more complicated jobs. A few examples are:

Door Bell - By turning an electromagnet on and off, a metal arm (or object) can be attracted over and over to the electromagnet causing the arm to hit a bell.

Solenoid - A solenoid is an electromagnet designed so that a plunger or metal object can be pulled or pushed back and forth. The starter in your car is basically a large solenoid. When you turn the key, the solenoid pushes the gears of the starter into the gears of the engine, causing the engine to turn and start. Once the engine is running on the burning gasoline, the solenoid pulls the gears back apart.

For more information on magnets, electromagnets, and their applications, see the web links below.
Buzzer and Bell This explains how doorbells work.
Auroras Paintings in the sky.
Electromagnets How electromagnets work.

And here is an experiments that you can run at home with a simple battery and some wires to explore how electromagnetism works.

Experiment 2 This is how your doorbell works.