If the critical angle for total internal reflection from a medium to vacuum is `30^(@)`, the velocity of light in the medium is

Options

A. `3 xx 10^(8)` m/s
B. `1.5 xx 10^(8)` m/s
C. `6 xx 10^(8)` m/s
D. `sqrt(3) xx 10^(8)` m/s

Answer

B

Explanation

n`= (1)/(sini_(c )) = (1)/(sin 30^(@)) = 2 `
`therefore " "v = (3 xx 10^(8))/(2) = 1.5 xx 10^(8) `m/s.