Question

An object shaped as ‘L’ is placed between two parallel plane mirrors as shown. In the first seven closest images, how many laterally inverted images are found?

A. 1
B. 2
C. 3
D. 4

Answer 1

Hint: If an object is situated in front of two mirrors, you may see images in both mirrors. In addition, the image in the first mirror may act as an object for the second mirror, so the second mirror may form an image of the image.

Complete step by step solution:

In the first can, the object is L, the two mirrors produce 2 laterally interval L images individually, this will become the object for second reflection and totally 2 images are formed.
In the second case the object is laterally inverted; the two mirrors will produce an image L individually. This will become an object for third reflection and totally 2+2=4 images are formed.
In the third case the object is L, the two mirrors produce 2 laterally inverted L images individually, this will become the object for fourth reflection and totally 4+2=6 images are formed.
In the fourth case the object is laterally inverted the two mirrors will produce an image L individually. This will become an object for next reflection and totally 6+2=8 images are formed.

Hence in total there are 4 laterally inverted images formed in the first seven closet images.

Note: Parallel plane mirrors facing each other form an infinite image of an object kept in between then regardless of the size of the mirrors.