Question

Two mirrors inclined to each other produces five images of an object placed between them. If the angle between them is reduced by ${30}^o$, what will be the number of images seen in the two mirrors.?

• A. 15
• B. 12
• C. 13
• D. 11

Answer 1

The correct option is D 11

$n=\frac{360}{\theta }-1$
$\therefore 5=\frac{360}{\theta }-1$
$\Rightarrow \theta ={60}^o$
On reducing the angle by ${30}^o$, the new angle between the mirror becomes ${30}^o$
Now, $\frac{360}{\theta }=\frac{360}{30}=12$
Since, this is an even number, number of images seen $=12-1=11.$