What is group and phase velocity?
What is group and phase velocity?
Waves can be in the group and such groups are called wave packets, so the velocity with a wave packet travels is called group velocity. The velocity with which the phase of a wave travels is called phase velocity. The relation between group velocity and phase velocity are proportionate.
How do I calculate phase velocity?
For this reason, phase velocity is defined as v p = ω / k .
How do you work out the velocity of a group?
In a given medium, the frequency is some function ω(k) of the wave number, so in general, the phase velocity vp= ω/k and the group velocity vg = dω/dk depend on the frequency and on the medium. The ratio between the speed of light c and the phase velocity vp is known as the refractive index, n = c/vp = ck/ω.
What is the main application and difference between phase and group velocity?
Phase velocity is defined for both, the single waves and superimposed waves. The group velocity is defined only to the superimposed waves. The group velocity is the velocity of the wave with lower frequency, but the phase velocity is the velocity of the wave with higher frequency.
Is phase velocity greater than c?
Mathematically: (1/lambdag)^2= (1/ lambda0)^2- (1/lambdac)^2, where lambdac is the cut off wavelength. Since the phase velocity is = lambda x f and f is the same then the guided phase velocity is greater than the free space wave velocity C, the speed of light.
Is phase velocity and wave velocity same?
Wave velocity, when not otherwise specified, usually means the phase velocity: the rate at which the phase travels in space. This site animates the differences between phase and group velocities. The group velocity is the speed at which energy is transported.
What do you mean by group velocity?
noun Physics. the velocity of finite numbers of waves undergoing simple harmonic motion, equal to the phase velocity when it does not vary with the wavelengths of the waves. The group velocity of the set of waves produced in water when a stone is dropped is less than the velocity of the individual waves.
Can group velocity be greater than phase velocity?
For most substances, therefore, the group velocity is smaller than the phase velocity. In such cases, it is mathematically possible that the group velocity may be larger than the phase velocity.
How is group velocity related to phase velocity?
Vg is the Group Velocity. Vp is the Phase Velocity. k is the angular wave number….Equation for the Phase Velocity of a Wave.
Chapter Related Topics | ||
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Relation Between Frequency And Velocity | P Wave | Period Angular Frequency |
What is the difference between phase velocity and group velocity *?
The main difference between Phase Velocity and Group Velocity is that phase velocity is greater than the group velocity in a normal medium.
What is physical significance of group velocity?
The group velocity is just the speed of these wave packets. From the dynamics view, group velocity has a physical significance– the rate of energy transport, which makes it more important than the phase velocity.
Can group velocity exceed speed light?
Usually, such reports deal with a phase velocity or group velocity faster than the vacuum velocity of light. However, as stated above, a superluminal phase velocity cannot be used for faster-than-light transmission of information.