Question

Two plane mirrors are placedplaced parallel to each other at a distance L apart . A point object O is placed betwen them , at a distance L/3 from one mirror .both mirrors form multiple images the distance between two images cannot be

A. 3L/2 B.2L/3 C.2L D.none

Answer 1

Option 1.
I guess the answer should be 3L/2.
since they are parallel mirrors, the total images formed is infinite (which is already in the question) and as it’s a plane mirror the image distance and object distance will be equal. so L/3 for one mirror menas 2L/3 from the other mirror. the image formed by L/3 object is L/3 for one mirror behind it and for the other mirror since it will act as an object at 2L/3 it forms image at 2L/3. so adding L/3+L/3 one image and 2L/3+2L/3 (the other image) is 2L. similarly if you consider two images by the same mirror it will be L/3+L/3 =2L/3 in one case and in the other case 2L/3+2L/3 =4L/3. thus i guess it could never be 3L/2. hope it helps :)