question_answer

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 ...

A)  \[\frac{y}{x}\]              

B)  \[\sqrt{\frac{x}{y}}\]

C)  \[\frac{x}{y-x}\]

D)  \[\frac{x}{y}\]