Question

a spherical mirror produces an image of magnification negative one by two on the screen when an object is placed at a distance 60 cm from it
A) calculate the focal length of the mirror
B) state the type of mirror
C) draw a ray diagram to show image formation in the above case

Answer 1

m=-v/u

-1/2=-v/-60

v=-30

1/f=1/v+1/u

1/f=1/-30-1/60

1/f=-90/1800

f=-20cm

therefore it is a concave mirror