In vacum, to travel distance d, light takes time t and in medium to travel distance 5d, it takes time T. The critical angle of the medium is

Options

A. `sin^(-1)((5T)/(t))`
B. `sin^(-1)((5t)/(3T))`
C. `sin^(-1)((5t)/(T))`
D. `sin^(-1)((3t)/(5T))`

Answer

C

Explanation

`._(m)mu_(a) = sin c`
`(V_(m))/(V_(a)) = sin c`
`((d_(m))/(t_(m)))/((d_(a))/(t_(a))) = sin c`
`((5d)/(T))/((d)/(t)) = sin c`
`(5d)/(T) xx (t)/(d) = sin c`
i.e., `c = sin^(-1)((5t)/(T))`.