Question

After tracing the path of rays of light through a glass slab for three different angles of incidence, a student measured the corresponding values angle of refraction r and angle of emergence e and recorded them in the table given below: (1) S. No. ∠i ∠i ∠e I 30° 20° 31° II 40° 25° 40° III 50° 31° 49° The correct observations are:(A) I and II(B) II and III(C) I and III(D) I, II and III

Answer 1

(D)For light rays passing through a glass slab, the following conditions should hold true:(1)(2)
Also, with the increase in incident angle, the refracted angle also increases.Both of these conditions are satisfied in all the three observations.

Answer 2

According to me the correct observation is option (d)