Question

Match the LIST-I with LIST-II 

LIST-I (Aberrations)	LIST-II (Consequences)
A. Spherical aberration	I. image of a point object as a disc
B. Coma	II. spreading of the image along the principal axis
C. Astigmatism	III. Line object is not imaged into a line
D. Distortion	IV. Image of a point object is a blurred surface

Choose the correct answer from the options given below:

• A. A - IV, B - I, C - II, D - III
• B. A - I, B - II, C - III, D - IV
• C. A - IV, B - I, C - III, D - II
• D. A - III, B - IV, C - I, D - II

Hint:

Remember the key features of aberrations:

\textbf{Spherical}: On-axis blur, affects the whole image.
\textbf{Coma}: Off-axis blur, comet-shaped.
\textbf{Astigmatism}: Off-axis blur, point becomes two lines.
\textbf{Distortion}: No blur, shape is wrong (pincushion/barrel).

Answer 1

The Correct Option is A

Step 1: Concept Overview:
This question tests your understanding of monochromatic optical aberrations and their effects on image formation.
Step 2: Detailed Explanation:
Here's an analysis matching each aberration to its corresponding image effect:


A. Spherical Aberration: Light rays passing through different lens zones converge at varying points, resulting in a point object appearing as a blurred surface instead of a sharp point. Therefore, A corresponds to IV.
B. Coma: This off-axis aberration causes an off-axis point object to appear comet-like. The "head" of this comet shape can be approximated as a point object imaged as a disc. Thus, B corresponds to I.
C. Astigmatism: Another off-axis aberration, astigmatism occurs when rays in different planes focus at different distances, leading to distinct line foci and spreading of the image along the principal axis. Hence, C corresponds to II.
D. Distortion: Distortion arises from magnification varying with distance from the optical axis. It deforms the image shape, meaning a line object is not imaged as a straight line. Consequently, D corresponds to III.

Step 3: Solution:
The correct matching of aberrations to their image effects is: A-IV, B-I, C-II, D-III.