Question

The figure shows two parallel plane mirrors. Object ${}^{\prime }{\text{O}}^{\prime }$ is placed $7\text{cm}$ from mirror $M_1$. Then, the distance of the final image from the mirror $M_1$ is

• A. $13\text{cm}$
• B. $10\text{cm}$
• C. $3\text{cm}$
• D. $7\text{cm}$

Answer 1

The correct option is D $7\text{cm}$

Since $M_1$ is a mirror, it will only allow reflection to take place and no light will be transmitted beyond the mirror $M_1$ towards the second mirror $M_2$.

Hence, virtual image formed by $M_1$ is at the same distance from the mirror as the distance between the object and the mirror.

(i.e) Image distance = Object distance

$\Rightarrow v=7\text{cm}$