Question

State the number of images of an object placed between the two plane mirrors, formed in each case when the mirrors inclined to each other at

(a) ${90}^{\circ }and\left(b\right){60}^{\circ }$.

Answer 1

(a) Angle between the mirrors, $\theta ={90}^o$

Now, $n=\frac{{360}^o}{{\theta }^o}=\frac{{360}^o}{{90}^o}=4$, which is even.

Hence number of images formed will be (n-1); i.e., 4 - 1 = 3 images

(b) Angle between the mirrors, $\theta ={60}^o$

Now, $n=\frac{{360}^o}{{\theta }^o}=\frac{{360}^o}{{60}^o}=6$, which is even.

Hence number of images formed will be (n-1); i.e., 6 - 1 = 5 images