Question

Question #382fc

Answer 1

We know the following relation between number of images `N` formed by two inclined mirrors and their angle of inclination `theta`

`N=360^@/theta-1`

In our problem `N=2`

So we have

`2=360^@/theta-1`

`=>theta=360^@/3=120^@`

The ray diagram of image formation is shown in above figure where two images are `O_1 and O_2` and the is object `O`. These three form the equilateral triangle `O_1O_2 O`

Given that the minimum distance between mirror and point source be `O_1O=O_2O= √3cm`

The length of each side of the equilateral triangle `=2sqrt3cm`

then the square of the side of the equilateral triangle is `=(2sqrt3)^2cm^2=12cm^2`