Characteristics Of Electromagnetic Waves

The inherent characteristic of electromagnetic waves is its frequency. According to Maxwell, varying the electric field gives rise to a magnetic field. An accelerated charge produces a time-varying magnetic field which in turn produces a time-varying electric field. Thus, an electromagnetic wave consists of sinusoidal time-varying electric and magnetic fields and both the fields are perpendicular to each other.

Looking for other study material?

You may also want to check out these topics given below!

• Transverse Nature of Electromagnetic Waves
• Electromagnetic Radiation
• Propagation Of Electromagnetic Waves

What are the Characteristics of Electromagnetic Waves?

Listed below are some important characteristics and properties of electromagnetic waves.

• Electromagnetic waves are transverse in nature as they propagate by varying the electric and magnetic fields such that the two fields are perpendicular to each other.
• Accelerated charges are responsible to produce electromagnetic waves.
• Electromagnetic waves have constant velocity in vacuum and it is nearly equal to
  \(\begin{array}{l}3 × 10^8 m s^{-1}\end{array} \)
  which is denoted by
  \(\begin{array}{l}C\end{array} \)
  =
  \(\begin{array}{l}\frac{1}{√{μ_o ϵ_o}}\end{array} \)
  .
• Electromagnetic wave propagation does not require any material medium to travel.
• The inherent characteristic of an electromagnetic wave is its frequency. Their frequencies remain unchanged but its wavelength changes when the wave travels from one medium to another.
• The refractive index of a material is given by:
  \(\begin{array}{l}n\end{array} \)
  =
  \(\begin{array}{l}√{μ_r ϵ_r}\end{array} \)
• Electromagnetic wave follows the principle of superposition.
• The light vector (also known as the electric vector) is the reason for the optical effects due to an electromagnetic wave.
• In an electromagnetic wave, the oscillating electric and magnetic fields are in the same phase and their magnitudes have a constant ratio. The ratio of the amplitudes of electric and magnetic fields is equal to the velocity of the electromagnetic wave.
  \(\begin{array}{l}C\end{array} \)
  =
  \(\begin{array}{l}\frac{E_0}{B_0} \end{array} \)
• The energy is carried by the electric and magnetic fields of electromagnetic waves are equal, i.e. the electric energy (
  \(\begin{array}{l}u_E\end{array} \)
  ) and the magnetic energy (
  \(\begin{array}{l}u_M\end{array} \)
  ) are equal;
  \(\begin{array}{l}u_E\end{array} \)
  =
  \(\begin{array}{l}u_M\end{array} \)
  .
• There is a vector quantity
  \(\begin{array}{l}S\end{array} \)
  , called the Poynting vector which represents the energy transferred by electromagnetic waves per second per unit area.