Different Forms of EM Waves

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Wave

• a disturbance in space

Crest

• highest point in a wave

Trough

• lowest point in a wave

Amplitude

• distance from the midpoint to the highest (or lowest) point of a wave

Wavelength

• the distance between two successive identical parts of a wave

Frequency

• refers to the number of waves produced in one second

Range

• refers to the extent or limits between which variation is possible

Electromagnetic Wave or Electromagnetic Radiation

• a wave that is created as a result of vibrations between an electric field and magnetic field

1862 → James Clerk Maxwell

predicted the existence of electromagnetic waves

1887

German physicist Heinrich Hertz, proved those waves were observed to exist

v

speed of propagation

f

frequency

λ

wavelength

c

299,792,458 m/s / speed of light

1. Radio Wave

2. Microwave

3. Infrared

4. Visible Light

5. Ultraviolet

6. X-ray

7. Gamma Ray

7 TYPES OF EM WAVES

Radio Wave

• a type of electromagnetic radiation with the longest wavelengths in the electromagnetic spectrum

• examples: radio/television signals, global positioning system, and magnetic resonance imaging

Microwaves

• a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively

• examples: satellite communication, terrestrial communication, cooking, and radio detection and ranging (radar)

Infrared

• an electromagnetic radiation with wavelengths longer than those of visible light and shorter than radio waves

• therefore invisible to the human eye

• example: remote control and thermal imaging through infrared scanners

Visible Light

• an EM wave that can be seen by human eye

• the sun is the only source of natural white light

• enables us to see things around us

• also gives light to the screen of most electronic devices

• example: artificial lights

Ultraviolet (UV)

• radiation in sunlight interact with a protein in the skin, converting it into vitamin D3, the active form of vitamin D, which is essential for maintaining healthy bones and teeth

• examples: security marking, sterilization of water in drinking fountains, and fluorescence

X-ray

• examples: diagnosing bone fractures and airport security scanner

Gamma Ray

• example: radiotherapy