Question

An object is placed perpendicular to the principal axis of a convex lens having focal length 10 cm. The distance of an object from the lens is 15 cm. Find the position of an image.Solve the given problem.(Ans: v = 30 cm)

Answer 1

Focal length(f) = 10 cm.

Object distance(u) = 15 cm. (negative)

Using the Lens Formula,

1/f = 1/v - 1/u

⇒ 1/10 = 1/v - (1/-15)

⇒ 1/v = 1/10 + 1/-15

⇒ 1/v = (3 - 2)/30

⇒ v = 30 cm.

Hence, the image is formed at the distance of 30 cm on the opposite side of the lens.

Hope it helps.