Question

An object 3cm high is placed at a distance of 20cm in front of a concave mirror of radius of curvature 50cm. Find the position and size of the image formed.

Answer 1

By using
1/v+1/u=1/f equation
1/v=1/f-1/u
1/v=1/50-1/20
1/v=-0.03
v=-33.33...
as v is negative so it's is a unreal image.
so it's position will be 33.33 cm behind from the mirror....
Now let's find the magnification by using
m=-v/u equation
so here m will be -33.33/-20=1.666..
as the object is is 3cm high then the image will be 3★1.666=5 cm
Hope it will help