Question

01. A thin convex lens has a focal length f. When an object is kept on one side at a distance of
d + Ad, it forms a real image at a distance of d A-d on the other side. If Ad << d, the focal
length of the convex lens fis nearly equal to
1) 2d
2)d
3) d/2
4) d/4​

Answer 1

A thin convex lens has a focal length f. When an object is kept on one side at a distance of

d + Ad, it forms a real image at a distance of d A-d on the other side. If Ad << d, the focal

length of the convex lens fis nearly equal to

answer is a) 2d