Question

A 2 cm high object is placed at a distance of 20 cm from a concave mirror. A real image is formed 40 cm from the mirror. Calculate the focal length of the mirror and the size of the image.

Answer 1

Answer:

since the images is real

so the distance of image from mirror is v=-40 CM

the distance of image from object is u =-20 CM

we know,

1/f=1/v+1/u=1/-20

f=-40/3 CM

know the magnification=m=-v/u

height of object h=2 CM

n=(2) (2) =4