An object is placed on the principal axis of concave mirror of focal length 10 cm at a distance of 8.0 cm from the pole. Find the position and the nature of the image.

Explanation

Here `u=-8.0 cm and f=-10cm`.

we have `1/f=1/u+1/v`
`or `1/v=1/f-1/u`
`=1/(-10cm)-1/(-8.0cm)`
`=1/(40cm)`
`v=40cm`
The position sign shows that the imasge is formed at 40 cm from the pole on the other side of the mirror ure. As the image is formed beyond the mirror, the reflected rays do not interect, the image is thus virtual.