If `._(i)mu_(j)` represents refractive index when a light ray goes from mefium `i` to medium `j`, then the product `._(2)mu_(1)xx._(3)mu_(2)xx._(4)mu_(3)` is equal to

Options

A. `._(3)mu_(1)`
B. `._(3)mu_(2)`
C. `._(4)mu_(1)`
D. `._(4)mu_(2)`

Answer

C

Explanation

`._(2)mu_(1) xx ._(3)mu_(2) xx ._(4)mu_(3) = (mu_(1))/(mu_(2)) xx (mu_(2))/(mu_(3)) xx (mu_(3))/(mu_(4))`
`= (mu_(1))/(mu_(4))`
`= ._(4)mu_(1)`