A ray is incident on interface of two media at critical angle as shown in the figure.

Options

A. if `mu_(1)` and `mu_(2)` both are increased by same amount the ray will suffer total internal reflection.
B. if `mu_(1)` and `mu_(2)` both are increased by same amount the ray will suffer refraction and angle of refraction will be less then `90^(@)`
C. if `mu_(1)` and `mu_(2)` both are doubled ray will suffer total internal reflection.
D. if `mu_(1)` ad `mu_(2)` both are doulbed ray will suffer refraction and angle of refraction will be less te `90^(@)`

Answer

B

Explanation

In given case
`sintheta=(mu_(2))/(mu_(1))`
if we increase both indices by `x`
`sini_(c)=(mu_(2)+x)/(mu_(1)+x)gt(mu_(2))/(mu_(1))` (since `mu_(1)gtmu_(2))`
`i_(c)gttheta`
Ray will suffer refraction. if `mu_(1)&mu_(2)` both are doubled critical angle will remain same, so the direction of refracted ray will remain same.