Electromagnetic Spectrum Applications

Study Notes

The electromagnetic spectrum is a range of wavelengths or frequencies of electromagnetic radiation
Types of electromagnetic radiation and their uses:
- Radio waves: Television transmission and radios, wavelength example: communication (long wavelengths), elephants
- Microwaves: Microwaves, weather and wifi, wavelength example: microwaves (shorter wavelengths), phones
- Infrared waves: Tv remote, collect thermal energy and heat lamps, wavelength example: heating lamps (shorter wavelengths), insects
- Visible light: Light/seeing, rainbow, wavelength: 400-700 nm
- Ultraviolet waves: Cause sunburns, uv lights in hospitals and sterilize medical equipment, wavelength: 100-400 nm, example: UV light, reptiles
- X-rays: Take images of bones, mammograms and checking for pneumonia, wavelength: 0.01-10 nm, example: Scanners, X-rays
- Gamma rays: Kill cancer cells and radioactive tracers

Definition: Throwing back from a boundary the wave encounters without absorbing it
Examples: Rear view mirror of cars, telescopes
Law of reflection: Angle of incidence = angle of reflection
Examples of use: Mirrors, reduction of heat
Effect of concave mirrors: Diverge
Effect of convex mirrors: Converge

Definition: Change light undergoes when it enters a different medium
Examples: Telescopes, form rainbows
Law of refraction: As light travels from a denser medium to a less dense medium, it bends away from the normal
Examples of use: Glasses, microscopes
Effect of bi-convex lens: Converge
Effect of bi-concave lens: Diverge

Definition: A disturbance of the organized movement of water, air, and light
Classification: Transverse (Light, microwave, UV, Ocean waves) or Longitudinal (Sound)
Wave properties:
- Frequency: Number of times a wave passes through a point per second
- Wavelength: Distance between crest and crest
- Amplitude: Height from point zero to crest
- Period: Time between crest and crest
- Trough: Lowest point of wave
- Crest: Highest point in wave
Wave speed formula: v = ƛ * f
Relationship between wavelength, frequency, and wave speed: As wave speed increases, frequency decreases