Which of the following statement(s) is/are correct?
(A) The power of a lens is the ability of the lens to converge or diverge the incident rays.
(B) S.I unit of the power of a lens is dioptre while focal length is in centimetres
(C) For a lens of larger focal length, power is smaller
(D) In any combination of lenses, the power of combination is not algebraic addition of power of combined lenses
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (A) and (C) only
Explanation:
(A) True — Power of a lens represents its ability to converge or diverge light rays.
(B) False — The S.I. unit of power is dioptre (D), but focal length is measured in metres, not centimetres.
(C) True — Power $P = \frac{1}{f}$, so a larger focal length means smaller power.
(D) False — For lenses in contact, the total power is the algebraic sum of their powers: $P = P_1 + P_2 + P_3 + \dots$