Characteristic Parameters of Electromagnetic Radiation:
The electromagnetic wave is feature in terms of a number of parameters. These are as follows:
Amplitude: It refers to the maximum height to that the wave oscillates and equals the height of the crests or depths of the troughs. That is a measure of the radiant power of the radiation. A radiant power refers to the energy of the radiation striking at a provided area per unit time. It is implies as P and is associated to the square of the amplitude. It is important to note that the radiant power is not associated to the wavelength. A closely related term is known as intensity of the radiation that is implies as I and is defined as the radiant power per unit solid angle.
Wavelength: It is the linear distance among two consecutive wave-crests or wave- troughs or the distance of complete cycle as display in Figure. It is represented through a Greek letter lambda (λ) and expressed in terms of metre (m), micrometre (µm), centimetre (cm), nanometre (nm) or Angstrom (Å) units. The wavelength of electromagnetic radiation varies from a few Angstroms to various metres.
Frequency: It is described as the number of wave crests or wave troughs which pass through a given point per second. It is represented through a Greek letter nu (ν) and expressed in terms of second inverse or per second (s -1) or Hertz (Hz). The relationship among wavelength and frequency is given as:
ν = c/ λ
While, the wavelength λ is in metres, the frequency ν is in reciprocal seconds (s -1) and the velocity of light, c = 3 × l08 m s -1.