Question

Which of the following statements is true?
(a) A convex lens has 4 dioptre power having a focal length 0.25 m.
b) A convex lens has 4 dioptre power having a focal length 0.25 m.
c) A concave lens has 4 dioptre power having a focal length 0.25 m.
d)A concave lens has 4 dioptre power having a focal length 0.25 m.​
Why not (d) as answer.

Answer 1

The  required Option (a) "A convex lens has 4 dioptre power having a focal length 0.25 m" is correct.

Explanation:

The power of a convex lens is positive.

∵ P = $\dfrac{1}{f}$

Hence, focal length of convex lens is also positive.

The  required Option (a) "A convex lens has 4 dioptre power having a focal length 0.25 m" is correct.

Answer 2

Answer:

option (a) is correct answer