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)sini`
B. `(1)/(sini)`
C. `(4)/(3)`
D. none of these

Answer

B

Explanation

Apply Snell.s law at glass-winter interface, we get `mu_(g)sini=mu_(w)sinr`
Apply Snell.s law at water air-interface, we get
`mu_(air)sin90^(@)=mu_(w)sinr`
`sinr=(1)/(mu_(w))=(3)/(4)`
Thus, `mu_(g)sini=(4)/(3)xx(3)/(4)=1`
or `mu_(g)=(1)/(sini)`