Arrow 2 5 Cm High Is Placed At Distance Of 25 Cm From Diverging Mirror Of Focal Length 20 Cm

An arrow 2.5 cm high is placed at a distance of 25 cm from a diverging mirror of focal length … the nature, position and size of the…

Answers:

h1= 2.5cm, u = -25cm, f = 20cm

We know that

1/v + 1/u = 1/f

⇒ 1/v + 1/-25 = 1/20

⇒ 1/v = 1/25 + 1/20 = (4 + 5)/100 = 9/100

∴ v = (100/9) cm = 11.1 cm

The image is formed 11.1 cm behind the convex mirror.
Now,

m = – (v/u) = h2/h1

⇒ – (11.1/-25) = h2/2.5

⇒ h2 = (11.1 × 2.5)/25 = 1.11 cm

The image is virtual, erect and 1.11 cm tall.