question_answer

A bulb is located on a wall. Its image is to be obtained on a parallel wall with the help of convex lens. If the distance between parallel walls is 'd' then required focal length of lens placed in between the walls is :-

A)  Only  \[\frac{d}{4}\]

B)  \[\frac{d}{2}\]

C)  More than \[\frac{d}{4}\] but less than \[\frac{d}{2}\]

D)  Less than or equal to \[\frac{d}{4}\]