CBSE Class 12-science Answered

Introduce a second lens (converging or diverging) depending upon the focus of the fixed lens, between the object and the first lens.The position of this new lens can be adjusted to obtain a sharp image on the screen. Adding another lens in the system changes the effective focal length of the lens system.This is done without disturbing the position of the object, the original lens or the screen.It is like what an eyeglasses do for people with poor vision. The second lens (eyeglasses) are inserted between the object and the lens of the eyes. The second lens is designed to correct the distortion of the eye lens, thus the image of the object is focused in the eye screen.