The speed of light in medium A is `2.0xx10^8m//sec` and that in medium B is `2.4xx10^8m//sec`. The critical angle of incidence for light tending to go from medium A to medium B is

Options

A. `sin^-1.(5)/(12)`
B. `sin^-1.(5)/(6)`
C. `sin^(-1).(2)/(3)`
D. `sin^(-1).(3)/(4)`

Answer

B

Explanation

`mu_Asini=mu_Bsinr`
`mu_AsinC=mu_Bsin90^@`
`(sinC)/(v_A)=1/v_B` (Since `muprop1/v`)
`sinC=v_A/v_B=(2)/(2.4)=5/6impliesC=sin^-1(5/6)`