Question

A student has obtained a point image of a distant object using the given convex lens. To find the focal length of the lens he should measure the distance between the : (A) lens and the object only (B) lens and the screen only (C) object and the image only (D) lens and the object and also between the object and the image

Answer 1

To find the focal length in such a case the distance between the image obtained and the optic centre should be measured

Answer 2

option (A) is correct answer