Electromagnetic theory: According to this theory
- Energy is emitted or absorbed continuously in the form of radiant energy.
- These radiations consist of electric and magnetic field acting perpendicular to the direction of propagation of wave.
- These waves can travel through medium as well as through vacuum.
- The radiations travel with speed =3x108m/sec.
Characteristics of wave
- Wavelength: It IS Distance between two crest or trough.
Units Used:- pm(picometer)
1 pm:- 10-12
1nm :- 10-9
1nm :- 10-10
- Frequency: number of waves produced in one second.
- Units Used:- sec-1, Hertz
- Velocity of light: It is distance travelled with respect to time in any direction.
- Units Used:- m/sec
- Amplitude: maximum displacement of particle from its mean position.
- Units Used:- m or cm
- Wave number: number of waves in 1cm length.