A parallel beam of light strikes a (i) plane mirror (ii) a convex mirror and (iii) a concave mirror. What is the deviation produced in each case in terms of the angle of incidence (i) ?

Explanation

In each case, angle of deviation `= 180^(@) - 2 i`. For example, for a ray striking a plane mirror normally, `I = 0, r = 0`, angle of deviation `= 180^(@)` i.e., the ray retraces its path on reflection.