A monochromatic beam of light is travelling from medium A of refractive index `n_(1)` to a medium B of refractive index `n_(2)`. In the medium A, there are x number of waves in certain distance. In the medium B, there are y number of waves in the same distance, Then, refractive index of medium A with respect to medium B is :

Options

A. `(x)/(y)`
B. `(y)/(x)`
C. `sqrt((x)/(y))`
D. `(x)/(y-x)`.

Answer

A

Explanation

(a) If x number of waves of wavelenght `lambda_(1) and y` number of waves of wavelenght `lambda_(2)` are present in same distance s, then
`s = xlambda_(1) = ylambda_(2)`
or " " `(x)/(y) = (lambda_(2))/(lambda_(1)) = (n_(1))/(n_(2))`
`therefore (n_(1))/(n_(2)) = (x)/(y)`.