question_answer

Light travels through a glass plate of thickness t and having a refractive index\[\mu \]. If c is the velocity of light in vacuum, the time taken by light to travel this thickness of glass is:

A)  \[t\,\mu \,c\]   

B)         \[\frac{t\,c}{\mu }\]

C)  \[\frac{t}{\mu \,c}\]                      

D)         \[\frac{\mu \,t}{c}\]