define refractiv index
Answers
The refractive index of a medium is defined as how the light travels through that medium. It is a dimensionless measure. It defines how much a light ray can bent when it enters from one medium to the other. Snell’s law clarifies the relation between the angle of incidence and angle of refraction. So, there are two formulas for calculating the refractive index of a medium. Let us imagine that a ray of light is traveling from a medium a to another medium b. Then conferring from Snell’s law,
\frac{sin\, i}{sin\, r}\, =\, n
n here, is a constant value which is recognized as the refractive index of medium b in regards to medium a.
The refractive index has no units as it is a ratio of two similar quantities.
Refractive index of a medium is also defined as the ratio of the speed of light in air or vacuum and the speed of light in that medium. If the speed of light in air is c and the speed of light in the medium is v then the refractive index of the medium is articulated as,
n\, =\, \frac{speed\, of\, light\, in\, vacuum}{speed\, of\, light\, in\, medium}\, =\frac{c}{v}