The length of the optical path of two media in contact of length `d_(1)` and `d_(2)` of refractive indices `mu_(1)` and `mu_(2)` respectively, is

Options

A. `mu_(1)d_(1) + mu_(2)d_(2)`
B. `mu_(1)d_(2) + mu_(2)d_(1)`
C. `(d_(1)d_(3))/(mu_(1)mu_(2))`
D. `(d_(1) + d_(2))/(mu_(3)mu_(2))`

Answer

A

Explanation

Optical path `N = mu t`
In medium 1, optical path `= mu_(1)d_(1)`
In medium 2, optical path `= mu_(2)d_(2)`
`therefore` Total path `= mu_(1)d_(1) + mu_(2)d_(2)`