• What do we mean by wavelength of EMW?

  • Wavelength of oscillating electric field or the oscillating magnetic field? Or is it that both the electric and magnetic field waves have same wavelength? If yes...

  • Why should they have same wavelength?

P.S. : I just have a superficial knowledge of electromagnetic radiation and waves


EM waves are formed when an electric field couples with a magnetic field. The magnetic & electric fields of an EM wave are perpendicular to each other & to the direction of the wave. The wavelength is just that--the length of the wave through one frequency cycle.

  • $\begingroup$ Yeah... But which wave? That's my question... Electric field doesn't interfere with magnetic field and give a single wave whose wavelength can be measured as their nature is different?.... Or is it that either the varying electric field generated magnetic field.. Or varying magnetic field generates the electric field (as in electromagnetic induction) ? $\endgroup$ – brainst Feb 3 '16 at 8:19
  • 1
    $\begingroup$ The E-field wave and the B-field wave are locked/coupled together in frequency, phase, wavelength, velocity and orientation. That is what an electromagnetic wave is. At birth both waves are produced as conjoined twins never to be separated. $\endgroup$ – Farcher Feb 3 '16 at 9:28
  • $\begingroup$ @brainst - the fields are coupled together--which constitutes the wave. $\endgroup$ – zeffur Feb 4 '16 at 7:41
  • $\begingroup$ @braist Wavelength is a well defined term for a planar infinite harmonic wave in free space. For such an ideal wave, the Maxwell equations stipulate that the electric and magnetic fields are proportional to each other in any point of space, except for their vectors being oriented differently. Then it is exactly as you write, temporal changes of magnetic field generate spatial changes of the electric one and vice versa. This makes the wave propagate forwards and everything is easy. Defining the wavelength near some dielectric structure or dipole is complicated. $\endgroup$ – dominecf Feb 4 '16 at 18:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.