Question

Two plane mirrors parallel to each other and an objective O placed between them.Then the distance of the first three images from the mirror $M_2$will be (in cm)

• A. 5,10,15
• B. 5,15,30
• C. 5,25,35
• D. 5,35,45

Answer 1

Answer: (C)

5,25,35

$\begin{array}{c}\text{The first image I will be formed by}{m}_2\text{as object is near.}\\ \text{at distance 5m inside}{M}_2\end{array}$

$\begin{array}{c}{\text{Now second image I}}_2\text{will form}10cm\text{inside}{M}_1\\ \text{So distance from}{M}_2=10+15=25cm\end{array}$

$\begin{array}{c}\text{Now first image Ii acts as object to}{M}_1\text{and forms}\\ {\text{third image I}}_3=20cm\text{inside}{M}_1\\ \text{So distance from}{M}_2=20+15=35cm\end{array}$