Question

An object shaped as '$L$' is placed between two parallel plane mirrors as shown. In the first seven closest images that are formed, how many laterally inverted images are formed?

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

The correct option is D 4

From the figure, the first seven closest images have been drawn,

Due to object $L$, Images $I_1$ and $I_2$ are formed.

Image $I_2$ acts as an object$O_1$ for $mirror1$ and produces the image $I_3$. While Image $I_1$ acts as an object $O_2$ for $mirror2$ and produces the image $I_4$ . This process continues.

Now, in the first 4 images we see that images $I_1$ and $I_2$ are laterally inverted. When these images $I_1\left(O_2\right)$ and $I_2\left(O_1\right)$ act as objects for $mirror2$ and $mirror1$, they produce the non laterally inverted image because lateral inversion of laterally inverted image takes place. Thus, in the set of first 4 images, 2 are laterally inverted.

Similarly, the process has been done for other continuous images.

In the figure, the encircled images show laterally inverted images.

So, for the first 7 images, there are 4 inverted images.

Hence, the correct answer is OPTION D.