Refractive index of a prism is `sqrt(7//3)` and the angle of prism is `60^(@)`. The minimum angle of incidence of a ray that will be tramitted through the prixm is

Options

A. `30^@`
B. `45^@`
C. `15^@`
D. None of these

Answer

A

Explanation

` theta_C=sin^-1(1/mu)`
`=sin^-1(sqrt((3)/(7)))=40.9^@`
`r_2=theta_C=40.9^@`
`r_1=A-r_2=19.1^@`
`mu=(sini_1)/(sinr_1)`
`sqrt((7)/(3))=(sini_1)/(sinr_2)`
Solving this equation, we get `i_1=30^(@)`