MHT CET20239 May 2023Evening ShiftPhysicsRay OpticsActual
If a ray of light in denser medium strikes a rarer medium at angle of incidence i , the angles of reflection and refraction are r and r^ respectively. If the reflected and refracted rays are at right angles to each other, the critical angle for the given pair of media is
Options
- A⁻¹ ( r^ )
- B⁻¹( i )
- C⁻¹( r)
- D⁻¹( i )
Correct answer
B. ⁻¹( i )
Step-by-step solution
According to Snell's Law, array ll & i r = 1 n & But i=r, & r r^ = 1 n & From figure r^ +r+90=180^ & r^ =180^ -90^ -r=90^ -r & r (90^ -r ) = 1 n & r r = 1 n array r = 1 n Critical angle is given by i_c= 1 n array ll & r= i_c & i_c= ⁻¹( r) array