Optics Question 27
Question: Assertion : There is no dispersion of light refracted through a rectangular glass slab. Reason : Dispersion of light is the phenomenon of splitting of a beam of white light into its constituent colours.
Options:
A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
B) If both assertion and reason are true but reason is not the correct explanation of the assertion.
C) If assertion is true but reason is false.
D) If the assertion and reason both are false.
E) If assertion is false but reason is true.
Show Answer
Answer:
Correct Answer: B
Solution:
After refraction at two parallel faces of a glass slab, a ray of light emerges in a direction parallel to the direction of incidence of white light on the slab.
As rays of all colours emerge in the same direction (of incidence of white light), hence there is no dispersion, but only lateral displacement.