Question

When a beam of white light is allowed to pass through convex lens parallel to principle axis, the different colors of light converge at different point on the principle axis after refraction. This is called

• A. scattering
• B. chromatic aberration
• C. spherical aberration
• D. polarisation

Hint:

Different colours have different refractive indices, so they focus at different points.

Answer 1

The Correct Option is B

Step 1: Idea:
Look at the word 'colours' in the question.

Step 2: Result:
A defect linked to colour is chromatic. Spherical aberration is linked to the aperture of the lens, not the colour, so only B fits.

Final Answer:
This defect is chromatic aberration, option (B). \[ \boxed{\text{Chromatic aberration}} \]