Question

An object is placed at a distance of 30 cm from concave mirror of focal length 20 cm . Where will the image be formed? Answer

Answer 1

The object is placed between focus and centre of curvature. so the image will be formed beyond the centre of curvature

Answer 2

Use mirror formula

(1/v +1/u=1/f) ---1

V=?

U=-30

F=-20

Therefore substitute in 1

1/v=1/30 -1/20

1/v=20-30/600

1/v=-1/60

Hence

V=-60