When the angle of incidence is `60^(@)` on the surface of a glass slab, it is found that the reflected ray is completely polarised. The velocity of light in glass is

Options

A. `sqrt(2)xx10^(8) m s^(-1)`
B. `sqrt(3)xx10^(8) m s^(-1)`
C. `2xx10^(8) m s^(-1)`
D. `3xx10^(8) m s^(-1)`

Answer

B

Explanation

As reflected light is completely polarized, therefore, `i_(p)=60^(@)`
`mu=tani_(p)=tan60^(@)=sqrt(3)`
As `mu=(c)/(v),v=(c)/(mu)=(3xx10^(8))/(sqrt(3))=sqrt(3)xx10^(8)ms^(-1)`