Question

If an object is placed symmetrically between two plane mirrors inclined at an angle of ${72}^{\circ }$, then the total number of images formed is:

• A. $5$
• B. $4$
• C. $2$
• D. Infinite

Answer 1

The correct option is B $4$

The number of images between two plane mirror inclined at an angle $\theta$ when the object is placed symmetrically between the mirrors is given as
$n=\frac{{360}^{\circ }}{\theta }-1$
Given,
$\theta ={72}^{\circ }$
$\therefore n=\frac{{360}^{\circ }}{{72}^{\circ }}-1=5-1=4$
Hence, the correct answer is OPTION B.