Question

How does the focal length of the lens change when red light incident on it is replaced by violet light? Give reason for your answer.

Answer 1

Answer:

Since violet light has a shorter wavelength compared to red light, focal length of a lens will decrease if red light is replaced by violet light. Hope that helps!! ... But refractive is inversely proportional to wavelength of light. Hence for more wavelength more is the focal length.

Answer 2

Answer:

Focal length of the convex lens increases with the increase in wavelength. We know wavelength of red is more than the wavelength of violet. So, as the wavelength decreases the focal length also decreases.