In some media EM Radiation is dispersed and in others it is

In some media EM Radiation is dispersed and in others it is not.

a.) Give an example of a dispersive medium fr visble light

b.) Give an example of a non-dispersive medium

c.) What property of the phase and/or group velocity of the wave indicates that a medium is dispersive?

Solution

a) If the speed of wave depends not only on the physical properties of the mediumbut also on frequency then it is called as dispersive medium. Example is glass prism which splits visible radiation as rainbow (VIBGYOR) colours.

b)If the speed of wave depends only on the physical properties of the medium i.e. independent of frequency then it is called as non-dispersive medium. Example is air as all the em wave travel with the velocity c in air.

c) The dependence of refractive of the medium on frequency causes the change in velocity with respect to the frequency.