Question

Calculate the number of images formed when two plane mirrors are held at an angle of 60 and 90 degree's

Answer 1

The number of images formed when two plane mirrors are held at an angle of 60 and 90 degree's is 5 and 3.

Explanation:

• We know the formula of number of image formed between two plane mirror which are at angle α degree.
• Number of image

        $\mathbf{\frac{360}{\alpha }= N \ or \ N-1}$

       N we take when ratio of  $\mathbf{\frac{360}{\alpha }}$ is odd

       N - 1 we take when ratio of  $\mathbf{\frac{360}{\alpha }}$ is even

• Now from question for $\mathbf{\alpha =60^{\circ}}$

        $\mathbf{Ratio \ \frac{360}{60 }=6}$

        So number of image formed = 6-1 =5

• Now from question for $\mathbf{\alpha =90^{\circ}}$

        $\mathbf{Ratio \ \frac{360}{90 }=4}$

        So number of image formed = 4-1 =3