Question

Something is mistaken here:
v — is the wave propagation velocity in the medium.
c — is the wave propagation velocity in the medium.

Answer 1

The velocity of propagation of light (wave) in a medium is given by:

$V=\frac{C}{n}$

Where

• Speed ​​of light in a vacuum. $C$
• Medium refractive index $n$
• Speed ​​of light propagation in the medium $V$

Now, it is possible to consider light as a wave, in that sense every statement is correct, but in physics c normally represents the velocity of light in a vacuum, therefore V must represent the velocity of light in a medium , under the aforementioned relationship.

The correct way to write the information is.

v — is the wave ( Light) propagation velocity in the medium.

c — is the wave (Light) propagation velocity in the vacuum.