Two plane mirrors are inclined to each other at 70° a ray of light is incident on one mirror the ray will undergo a total deviation ofA. 180°B. 220°C. 40°D. Can't be found because angle of incidence us not given

Because of the reflection of light perpendicular to the First mirror.....it takes an angle of 90 degrees and since it is incident on the other plane mirror So it will take an angle of 90 degrees as well...if we calculate this all....we will find it will undergo a total deviation of 90 + 90 =180....For every plane mirror of any angles....