To find the focal length of a convex lens in a laboratory, Aman fixed it on a stand and kept it on a mark of 15.3cm on an optical bench.To get a clear image of a distant tree, he adjusted a screen and finally got the clear image when the screen was placed at 32.5cm. Then Focal length of the lens is.........
focal length = distance b/w the lens and the screen
focal length = 32.5 cm - 15.3 cm
hence the focal length of the lens is 17.2 cm