Question

An object of height 5cm is placed on 30cm distance on the principal axis in front of a concave mirror of focal length 20cm. Find the image distance and size of the object.

Answer 1

Hope it helps you....

Answer 2

Answer:

Image Distance = 60cm

Size of the Image = 10cm

Explanation:

Object distance (u) = -30cm

Focal Length (f) = -20cm

Height of the Object ($h_o$) = 5cm

Image distance (v) = ?

Height of the Image ($h_i$) = ?

Mirror Formula: 1/f = 1/u + 1/v

= 1/-20 = 1/-30 + 1/v

= -1/20 + 1/30 = 1/v = -3 + 2/60 = 1/v ⇒ - 1/60 = 1/v

= v = -60cm

∴ Image distance is 60cm from the mirror.

= Magnification (m) = -v/u = -(-60)/-30 = -2

Again, m = $h_i/h_o$ ⇒ -2 = $h_i$/5 = $h_i$ = -10cm

∴ The image is Real, Inverted with a height if 10cm.