For two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
(a) Both A and R are true, and R is correct explanation of the assertion.
(b) Both A and R are true, but R is not the correct explanation of the assertion.
(c) A is true, but R is false.
(d) A is false, but R is true.
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 constituents’ colours.
(b) Both A and Rare true, but R is not the correct explanation of the assertion.
Explanation:
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 same direction, hence there is no dispersion only lateral displacement takes place.