A ray of light, travelling in a medium of refractive index 'mu_, is incident at an angle i on a composite transparent plate consisting of three plates of refractive indices `mu_1,mu_2 and mu_3.` The ray emerges from the composite plate into a medium of refractive index `mu_4,` at angle x. Then,

Options

A. sin x=sini
B. sinx=`mu/(mu_(4))sini`
C. `sinx=(mu_(4))/musini`
D. `sinx=(mu_(1))/(mu_(2))(mu_(3))/(mu_(2))(mu)/(mu_(4))sini`

Answer

B

Explanation

(b) From Snell's law,
`musin i=`constant
`mu_(4)sinx=musini`
`therefore sinx=mu/mu_(4)sini`