Question

In Fig., find the total magnification after two successive reflections first on $M_1$ and then on $M_2$.

• A. $+1$
• B. $-2$
• C. $+2$
• D. $-1$

Answer 1

Answer: (C)

$+2$

For $M_1:V=-60,m_1=-2$
For $M_1:u=+20,F=10$
$\frac{1}{V}=\frac{1}{20}=\frac{1}{10}\Rightarrow V=20$
$\therefore M_2=-\frac{20}{20}=-1$
$\therefore M=m_1\times m_2=+2$.