Question

Two plane mirrors $M_1$ and $M_2$ are placed at an angle of ${90}^{\circ }$. A point object is at a distance of $d$ and $l$ from mirrors $M_1$ and $M_2$ respectively. Then

• A. Number of images formed are 2
• B. Images formed lie on a circle with P as a centre and radius $\sqrt{d^2+l^2}$
• C. Number of images formed are more than 2
• D. None of these

Answer 1

Answer: (B), (C)

Number of images formed are more than 2

The images formed can be found by retracing all possible rays are shown in the diagram.


Clearly there are more than two images formed

Distances from point P to each of $I_1,I_2$ and $I_3$ is $\sqrt{d^2+l^2}$. So the locus is a circle with radius $\sqrt{d^2+l^2}$.