`""_(i)u_(j)` represents refractive index when a light ray goes from medium I to medium j, then the product `""_(2)µ_(1)xx``""_(3)µ_(2)xx``""_(4)µ_(2)` is equal to

Options

A. `""^3mu_1`
B. `""^3mu_2`
C. `1/(""^1mu_4)`
D. `""^3mu_1`

Answer

C

Explanation

`""^2mu_1 xx ""^3mu_2 xx ""^4mu_3 = (mu_1)/(mu_2) xx (mu_2)/(mu_3) xx (mu_3)/(mu_4)`
`""^2mu_1 xx ""^3mu_2 xx ""^4mu_3 = (mu_1)/(mu_4)`
`""^2mu_1 xx ""^3mu_2 xx ""^4mu_3 = ""^4mu_3 = ""^4mu_3 = mu_1 = 1/(""^1mu_4)`