A ray of light is incident at the glass-water interface at an angle `i` it emerges finnaly parallel to the surface of water, then the value of `mu_(g)` would be

Options

A. `(4//3) sin i`
B. `1//sin i`
C. `4//3`
D. 1

Answer

B

Explanation

We know that according to Snell.s law we can write the following:
`mu sin theta = "constant"`
At the first refraction we can write the following:
`mu_(g)sini=(4)/(3)sinr" ….(1)"`
At the second refraction we can write the following :
`(4)/(3)sinr=1sin 90=1`
Substituting the above in equation (1) we get
`mu_(g)=1//sini`
Hence, option (b) is correct.