Match List-I (ray falling on a lens) with List-II (path of the ray after refraction).
| List-I | List-II |
|---|---|
| (A) A ray parallel to the principal axis falls on a convex lens | (I) Emerges parallel to the principal axis |
| (B) A ray parallel to the principal axis falls on a concave lens | (II) Passes through the second principal focus |
| (C) A ray passes through the optical centre of a thin lens | (III) Appears to diverge from the first principal focus |
| (D) A ray passes through the first principal focus of a convex lens | (IV) Emerges without any deviation |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A)-(II), (B)-(III), (C)-(IV), (D)-(I)
(A) A ray parallel to the principal axis falls on a convex lens — This matches (II). A convex lens converges the ray, and it passes through the second principal focus F′ on the far side.
(B) A ray parallel to the principal axis falls on a concave lens — This matches (III). A concave lens spreads the ray out, so it appears to come from the first principal focus F on the incident side.
(C) A ray passes through the optical centre of a thin lens — This matches (IV). A ray through the optical centre of a thin lens is not bent. It goes straight on after refraction.
(D) A ray passes through the first principal focus of a convex lens — This matches (I). The convex lens bends this ray towards the axis just enough to make it come out parallel to the principal axis.
NCERT (2026-27):
Refraction by a lens – “(i) A ray emanating from the object parallel to the principal axis of the lens after refraction passes through the second principal focus F′ (in a convex lens) or appears to diverge (in a concave lens) from the first principal focus F.”
Refraction by a lens – “(ii) A ray of light, passing through the optical centre of the lens, emerges without any deviation after refraction.”
Refraction by a lens – “(iii) (a) A ray of light passing through the first principal focus of a convex lens … emerges parallel to the principal axis after refraction.”