08-11-2012, 04:47 PM
Electromagnetic Waves
Electromagnetic Waves.ppt (Size: 40 KB / Downloads: 40)
What are Electromagnetic Waves?
Electromagnetic Waves are made by vibrating electric charges and can travel through space.
The transfer of energy by electromagnetic waves is called radiation.
Electromagnetic waves do not need a medium to travel through (they can travel through a vacuum).
Electric & Magnetic Fields
Electric & Magnetic fields – Related forces that operate even in empty space.
A moving electric charge creates a magnetic field.
Changing magnetic fields create changing electric fields and vice versa.
Electromagnetic waves are produced when an electric charge is vibrating.
Vibrating electric charges are surrounded by vibrating electric and magnetic fields.
Vibrating electric and magnetic fields travel outward from the moving charge.
Electromagnetic fields carry radiant energy.
Wave Speed
Each type of electromagnetic wave differs in the size of their wavelength, however, all waves travel at the same speed, which is the speed of light.
The speed of light is 186,000 miles per second. (300,000 km/s)
Electromagnetic waves slow as they travel through matter.