ray-optics-and-optical-instruments Question 20
Question: Q. 5. A short pulse of white light is incident from air to a glass slab at normal incidence.
After travelling through the slab, the first colour to emerge is (a) blue. (b) green. (c) violet. (d) red.
[NCERT Exemplar]
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Solution:
Ans. Correct option : (d)
Explanation : As we know that the velocity of wave is :
When light ray goes from one medium to other medium, the frequency of light remains unchanged. So,
