ray-optics-and-optical-instruments Question 2
Question: Q. 2. The direction of ray of light incident on a concave mirror is shown by $P Q$ while directions in which the ray would travel after reflection is shown by four rays marked 1, 2, 3 and 4 (Figure). Which of the four rays correctly shows the direction of reflected ray?
(a) 1.
(b) 2 .
(c) 3 .
(d) 4. [NCERT Exemplar]
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Solution:
Ans. Correct option : (b)
Explanation : Incidence ray $P Q$ is coming through principal focus $F$ so it must be parallel to principal axis, that is, either 2 or 4 .
As it is a concave mirror so, ray cannot go behind the mirror so ray (4) is discarded.
So, ray 2 is the reflected ray.
