Question

The 'D' (protractor) used for measuring the angle of incidence (∠i) and the angle of reflection (∠r) , has to be positioned in the ways illustrated in figures: For angle of incidence For angle of reflection
a) X and Y respectively b) W and Z respectively
c) X and Z respectively d) W and Y respectively

Answer 1

Answer:

Place two pins on the ray and mark them as Q and R. ... Therefore, the protractor must be placed on the normal because the angle of incidence, refraction and emergence are made by the light ray with the normal. Hence, the correct option is (d).

Answer 2

Answer:

option d is correct - w and y respectively