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
Answer & explanation
Correct answer: option 4
We know,
v = fλ ⇒ v ∝ λ [ ∴ f = constant]
Thus the velocity of red light is highest , so first colour to emerge will have longest wavelength i.e. Red.