In figure, a point source S is placed at a height h above the plane mirror in a medium of refractive index `mu`.
a. Find the number of images seen for normal view.
b. Find the distance between the images.

Explanation

a. To observer in air, there are two objects placed in the medium of refractive index `mu` . One is the actual object S and the other object is `S^(')` which is the image of S in the plane mirror.
The observer is able to see two image, one for each object.
b. For observer in air, apparent depth
`h^(')=(h)/(mu)`
Hence distance between two images will be `2h^(')=(2h)/(mu)`