Phase velocity and group velocity

nchodenchode Forum Coordinator Posts: 0
Can anyone help me with how to differentiate phase velocity and group velocity?


  • rtkrtk Pune, IndiaPosts: 167Forum Coordinator
    Suppose, we add several waves together to create a resultant wave pattern. Each of these original waves can be of different velocity, amplitude and/or wavelength. So the velocity with which the phase of a single wave (original wave) travels is called phase velocity and the velocity of the resultant wave pattern refers to group velocity. Hope it addressed your concern!
  • nchodenchode Posts: 540Forum Coordinator

    Thank you for the response.

    Is there any general relation between phase velocity and group velocity?

  • cblaircblair Posts: 102Forum Coordinator


    The group velocity is directly proportional to the phase velocity and it differs for dispersive and non-dispersive waves. For non-dispersive waves, group velocity (Vg) is equal to the phase velocity (Vp) whereas, for dispersive waves Vg = Vp +k(dVp/dk), where is the angular wave number.

  • nchodenchode Posts: 540Forum Coordinator
    That really helped. Thank you!
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