A convex lens of focal length fis placed in front of a

Last updated: 7/10/2022

A convex lens of focal length fis placed in front of a screen. A point source of light is placed at some distance, (f< d < 4f) from the screen. A circular spot of light is formed on the screen. The lens is moved between source and screen starting from the position of source, then As lens is moved away from source towards screen, size of spot remains constant As lens is moved away from source towards screen, size of spot decreases continuously As lens is moved away from source towards screen, size of spot keep on increasing As lens is moved away from source size of the spot first decreases then increases