Electromagnetic Spectrum

WHAT IS IT?

• The electromagnetic spectrum is the complete spectrum or continuum of light including radio waves, infrared, visible light, ultraviolet light, X-rays and gamma rays

• An electromagnetic wave consists of electric and magnetic fields which vibrates thus making waves.

RADIO WAVES

• Low energy waves with long wavelengths• Includes FM, AM, radar and TV waves• Wavelengths of 10-1m and longer• Low frequency • Used in many devices such as remote

control items, cell phones, wireless devices, etc.

RADIO WAVES

Longest wavelength EM waves Uses:

TV broadcasting AM and FM broadcast radio Avalanche beacons Heart rate monitors Cell phone communication

MICROWAVES

Wavelengths from 1 mm- 1 m Uses:

Microwave ovens Bluetooth headsets Broadband Wireless Internet Radar GPS

INFRARED RADIATION

Wavelengths in between microwaves and visible light

Uses: Night vision goggles Remote controls Heat-seeking missiles Thermogram—a picture that shows

regions of different temperatures in the body. Temperatures are calculated by the amount of infrared radiation given off. Therefore people give off infrared rays.

Heat lamps give off infrared waves.

VISIBLE LIGHT

The only portion of EM wave able to be detected by the human eye.

Traditionally, we break white light into red, orange, yellow, green, blue, indigo, and violet (ROY G BIV)

Red light has a frequency of roughly 4.3 × 1014 Hz, and a wavelength of about (700nm).

Violet light, at the other end of the visible range, has nearly double the frequency—7.5 × 1014 Hz—and (since the speed of light is the same in either case) just over half the wavelength—

(400nm).

ULTRAVIOLET

Shorter wavelengths than visible light Uses:

Black lights Sterilizing medical equipment Water disinfection Used to kill bacteria. (Sterilization of

equipment)

Security images on money

X-RAYS

Tiny wavelength, high energy waves

Uses: Medical imaging Airport security Inspecting industrial welds

GAMMA RAYS

Smallest wavelengths, highest energy EM waves (blocked by ionosphere)

Uses Food irradiation Cancer treatment Treating wood flooring