An index of refraction less than one for a medium would imply that?

A)the speed of light in the medium is greater than the speed of light in vacuum.


B)the speed of light in the medium is the same as the speed of light in vacuum.


C)refraction is not possible.


D)reflection is not possible.

An index of refraction less than one for a medium would imply that?
A
Reply:(C) is the answer. Some plasmas have an index of refraction less than one. We recently worked a problem where the ionosphere had an index of refraction - for certain frequencies - of 0.8.





Because the index of refraction is less than one, *any* angle of incidence is the critical angle, leading to total internal reflection. Thus, refraction is not possible and all waves reflect.





Again, this is just for a certain frequency range.
Reply:Well, since the index of refraction for vacuum is defined as 1, then B cannot be true.


Furthermore, since refraction is a result of the change in speed when light moves from one density to another, there's no reason that reflection or refraction could not work just because one of the densities was less then that of vacuum.


So D and C can't be true either.
Reply:Refractive index of air or vaccum is one.


It is the least refractive index possible.


So answer is C.





If u have doubt about that ,check what u have studied..