scienceeceics
Electromagnetic waves
Electromagnetic waves
Are transverse oscillating waves composed of electric and magnetic fields.
Travels in a vacuum (without a medium)
Invisible energy
Electric wave ( E wave) up and down
Magnetic wave ( M wave) side to side
Types of radiation
non - ionizing
weak, not enough energy
Warms up
Non-ionizing radiation is a type of electromagnetic radiation that doesn't have enough energy to remove an electron from an atom or molecule.
Ionizing
Strong
Ionizing radiation refers to radiation that has enough energy to break an electron away from an atom, a process called ionization.
Properties of EM
They carry energy
Photons, tiny packets of light energy
They travel in a vacuum
Travels at the same speed
The speed of light is 300,000 km/s in a vacuum
EM are transverse waves (sideways)
Longitudinal ( push and pull )
they obey the wave equation
V- velocity
F- frequency
λ - wavelength
Hertz no. of wavelengths in one second
Frequency
Number of wavelengths per second
Wave speed
tells us how fast the wave travels.
Wavelength
tells us how long each wave is.
EM spectrum and its applications
EM waves are classified according to their frequencies
They are also described according to their wavelengths and energies
Different types of EM waves
waves | description | uses | bands | Ionizing or non-ionizing |
Radio | Lowest frequency Longest wavelength | RFID, television, and FM and AM radio broadcasts | ELF,VLF,LF,MF,VHF, AND UHF | non-ionizing |
Microwave | Higher frequency than radio waves | Bluetooth and wifi | L, S, C, X, and K, | non-ionizing |
Infrared | Found between micro and visible light | Remote controls, thermal imaging | NEAR,MIDDLE AND FAR | non-ionizing |
Visible Light | Can be seen by the unaided eye | photography and illumination | ROYGBIV | non-ionizing |
Ultraviolet | Extends from the violet spectra of the visible light | killing bacteria | UVA, UVB, UVC | ionizing |
X -rays | Between the UV and gamma Their wavelengths are so small | X-ray machines | SOFT AND HARD | Ionizing |
Gamma | Found at the end of the EM spectrum Contains the highest energy of all | Kills cancer | NONE | Ionizing |