Light travels in two media A and B with speeds `1.8 × 10^(8) m s^(–1) and2.4 × 10^(8) m s^(–1)` respectively. Then the critical angle between them is

Options

A. `sin^(-1) ((2)/(3))`
B. `tan^(-1) ((3)/(4))`
C. `tan^(-1) ((2)/(3))`
D. `sin^(-1) ((3)/(4))`

Answer

D

Explanation

`sin i_(c ) = (v_(A))/(v_(B)) = (1.8 xx 10^(8))/(2.4 xx 10^(8)) = (3)/(4) " as " v prop (1)/(n)`
`therefore " " i_(c ) = sin^(-1) ((3)/(4))` .