Question

Match the number of images formed by two plane mirrors with the corresponding angle between them, when the object is placed symmetrically between them.

• A. 5
• B. 2
• C. 3
• D. 1

Answer 1

When two plane mirrors are placed at some angle, multiple images of an object are formed.
Since the object is placed symmetrically between the mirrors, the number of images formed is given by the formula: $N=\left(\frac{360}{\theta }\right)-1$; where $\theta$ is the angle between the two plane mirrors in degrees.
Therefore, when
$for\theta ={60}^{\circ },N=\left(\frac{360}{60}\right)-1=5for\theta ={120}^{\circ },N=\left(\frac{360}{120}\right)-1=2for\theta ={90}^{\circ },N=\left(\frac{360}{90}\right)-1=3for\theta ={180}^{\circ },N=\left(\frac{360}{180}\right)-1=1$