Glass has refractive index `mu` with respect to air and the critical angle for a ray of light going from glass to air is `theta`. If a ray of light is incident from air on the glass with angle of incidence `theta`, the corresponding angle of refraction is

Options

A. `90^(@)`
B. `sin^(-1) ((1)/(mu^(2)))`
C. `sin^(-1) ((1)/(mu))`
D. `sin^(-1) ((1)/(sqrtmu))`

Answer

B

Explanation

For the ray going from glass to air , critical angle = `theta` and `sin theta = (1)/(mu) " " … (1)`
`therefore mu = (sin theta)/( sin r) " " … (2)`
`therefore` Using (1) in (2) , we get
`mu = (1)/(mu) xx (1)/(sin r)`
`therefore sin r = (1)/(mu^(2)) therefore r= sin^(-1) ((1)/(mu^(2)))`