Question

To get three images of a single object, we should have two plane mirrors at an angle of

• A. ${60}^o$
• B. ${90}^o$
• C. ${120}^o$
• D. ${30}^o$

Answer 1

The correct option is B ${90}^o$

Number of images $N$, formed in two mirrors inclined at an angle $A$ to each other is given by:

$N=360/A-1$

Given: $N=3$

Hence, $3=360/A-1$

$3+1=360/A$

$4=360/A$

$A=360/4={90}^0$