Question

A ray of light travels from an optically denser to rarer medium. The critical angle for the two media is c. The maximum possible deviation of the ray will be

A ∏ - c

B ∏ - 2c

C 2c

D ∏/2 + c

Answer 1

The maximum possible deviation of a ray of light going from a denser to a rarer medium at the critical angle is π - c, where c is the critical angle.

Step-by-step explanation:

When a ray of light travels from an optically denser medium to a rarer medium and the incident angle is greater than the critical angle, the phenomenon of total internal reflection occurs. The critical angle (c) is defined as the incident angle that results in an angle of refraction of 90°. If we consider the geometry of the situation where the refracted ray is at 90° to the normal, the maximum deviation of the light ray will occur when it just grazes along the interface at the critical angle. In this case, the deviation (D) is equal to 180° - c (from the normal back to the incident direction) plus the incident angle, which is also c. Therefore, the maximum deviation D is given by: D = 180° - c + c = 180° = π (in radians). So the correct answer is A (π - c).