Question

Which of the following is used to reduce chromatic aberration in lenses?

• A. Convex lens
• B. Concave lens
• C. Achromatic combination
• D. Cylindrical lens

Hint:

Achromatic lenses are designed by combining different types of lenses (concave and convex) to correct chromatic aberration, especially in telescopes and microscopes.

Answer 1

The Correct Option is C

Step 1: Understanding chromatic aberration.
Chromatic aberration occurs due to the dispersion of light into its constituent colors (spectrum). This happens because different colors (wavelengths) of light refract at different angles when passing through a lens, leading to color fringing. Step 2: Solution to chromatic aberration.
An achromatic combination (made by combining a convex lens and a concave lens of different materials) is designed to minimize chromatic aberration. This combination corrects the color distortion by canceling out the effects of dispersion.
Step 3: Conclusion.
Thus, an achromatic combination is used to reduce chromatic aberration in lenses.
\[ \boxed{\text{Achromatic combination}} \]