Question

how can you determine the approximate focal length of convex lens? plz give the ans in short!​

Answer 1

Explanation:

By moving the convex lens to and fro along the scale, focus a distant object on wall. The image which forms on the wall is very near to the focus of the lens and the distance of the lens from the image is read directly by the metre scale. This gives the approximate focal length of the lens.

hope it helps