Question

Two plane mirrors are placed making an angle θ in between them. Write an expression for the number of images formed of an object placed in between the mirrors. State the condition, if any. 

Answer 1

If two mirrors make an angle  with each other and object is placed in between the two mirrors, the number of images formed is n or (n - 1) depending upon n = 360^o / ^o is odd or even.

(a) If n = 360^o / ^o is odd,

(i) The number of images formed is n, when the object is placed asymmetrically between the mirrors.

(ii) The number of images formed is n-1, when the object is placed symmetrically between the mirrors.

(b) If n = 360^o / ^o is even, the number of images is always n-1.