COMEDK2018PhysicsRay Optics
A ray of light enters from a rarer to a denser medium. The angle of incidence is i . Then, the reflected and refracted rays are mutually perpendicular to each other. The critical angle for the pair of media is
Options
- A⁻¹( i)
- B⁻¹( i)
- C⁻¹( i)
- D⁻¹( i)
Correct answer
C. ⁻¹( i)
Step-by-step solution
The angle of incidence =i Let r be the angle of refraction. According to given situation, reflected rays and refracted rays are perpendicular to each other. i.e. i+r=90^ According to Snell's law, aligned &= i r &= i (90-i) [ From Eq. (i) ] &= i i &= i aligned If i_ C be the critical angle for the pair of media, then = 1 i_ C From Eas. (ii) and (iii), we get i= 1 i_ C i_ C = i i_ C = ⁻¹( i)