A ray of light passes from vaccum into a medium of refractive index n. If the angle of incidence is twice the angle of refraction, then the angle of incidence is

Options

A. `2cos^(-1)((mu)/(2))`
B. `sin^(-1)(mu)`
C. `sin^(-1)((m)/(2))`
D. `cos^(-1)((mu)/(2))`

Answer

A

Explanation

`mu=(sini)/(sinr)" "because i=2r`
`rArr mu=(sin2r)/(sinr)=(2sin r.cosr)/(sinr)`
`r=cos^(-1)((mu)/(2)), therefore i=2cos^(-1)((mu)/(2))`