Question

find the position ,nature and size of image of an object 3 cm height placed at a distance 9 cm from a concave mirror of focal length 18 cm ​

Answer 1

object distance, u = -9 cm

focal length, f = -18 cm

we know, mirror formula, 1/f = 1/v + 1/u

                                         1/-18 = 1/v + (-1/9)

                                          1/v = (-1/18) + (1/9)

                                          v = 18/(-1+2) = 18 cm

now, magnification formula for mirror, -v/u = h'/h

where, h'= image's height and h = object's height

therefore, -18/-9 = h'/3

                  h' = 6 cm

hence,

the image will be formed on the other side of the mirror, 18 cm away from it and it would be virtual and erect in nature and larger than the object..

THANKS!!!