1. Electromagnetism Utilizing electricity to create and use magnetic fields

2. Electricity and Magnetism
Relationship discovered in 1820 by Danish scientist Hans Christian Oersted
Electricity and Magnetism are different parts of one force called the electromagnetic force
Moving electric charges create a magnetic field

3. Solenoids & Electromagnets
When a wire carrying a current is looped, the magnetic fields combine to make the wire act like a bar magnet
The field through the center is very strong.
Loop it more, it gets stronger

4. Solenoids & Electromagnets
A coil of current-carrying wire that causes a magnetic field is called a solenoid
Place a ferromagnetic (iron based) material in the middle of the coil…you have an electromagnet (This greatly increases the strength of the magnetic field produced by a solenoid)

5. Solenoids & Electromagnets
Changing the current in the wire controls the strength and direction of the magnetic field produced
The current can also be used to turn the magnetic field on and off. Scientists manipulate current and magnets when making devices we use every day

6. Solenoids & Electromagnets
The strength of an electromagnet depends on:
The current in the solenoid (more current  more strength)
The number of loops in the coil (more loops  more strength)
The type of material in the core

7. Electromagnetic Devices
Electromagnets can take electrical energy (from the moving electrons in current) and change it into motion that can do work
Electromagnetic devices thus change electrical energy into mechanical energy
Door bells
Electric motors
Loudspeakers
Galvanometers

8. Galvanometers Measure small amounts of current using a solenoid
Used in gas gauges where a sensor in the gas tank reduces current as the tank gets low

9. Electric Motors Use an electromagnet to turn an axle
When current flows, one side of the armature is pushed and the other is pulled
Current continues to change direction, which causes the axle to spin

10. Electromagnets at Work!