The time taken by the light to cross a glass of thickness 4 mm and refractive index `(mu = 3)`, will be

Options

A. `4 xx 10^(-11) sec`
B. `16 xx 10^(-11) sec`
C. `8 xx 10^(-11) sec`
D. `24 xx 10^(-11) sec`

Answer

A, C, D

Explanation

Time , t `=("Thickness of glass")/("Speed of light in glass")=(d)/(c//a)=(mud)/(c)=(3xx4xx10^(-3))/(3xx10^(8))=4xx10^(-11)s`