Question

An object is placed on the principal axis of a concave mirror of focal length 10 cm at a distance of 8 cm from the pole, find the position and nature of the image ?

Answer 1

Answer :-

• Image distance is 40 cm.

Explanation :-

Given :

• Object distance (u) = -8 cm
• Focal length (f) = -10 cm

To find :

• Image distance (v)
• Nature of the image

Solution :

Using the mirror formula :

• 1/f = 1/u + 1/v

Substituting we values,

→ 1/v = 1/-10 - 1/-8

→ 1/v = 4 - 5/-40

→ 1/v = -1/-40

→ 1/v = 1/40

→ v = 40 cm

• Image distance is 40 cm.
• The positive sign shows that the image is formed at 40 cm from the pole on the other side of the mirror. As the image is formed beyond the mirror, the reflected rays do not intersect, thus the image is virtual.