An object of height 3 cm is placed in front of a convex lens of focal length 10 cm at a distance of 15 cm.

What is the distance of the image formed?

Given-

Lens using: convex

The height of object: 3cm

The focal length of lens: 10cm

The object is placed at 15 cm from the optical center

The formula of the lens:

So, let suppose image is formed at a distance of v cm from the optical center

Ray diagram will look something like this:

Here (from sign convention direction of incident light is left to right)

AB = object = +3cm (upward direction from x-axis)

CF = focal length = 10 cm (direction is C to F (right side) i.e. left to right same as direction of incident light)

CB = u = - 15 cm (direction is C to B i.e. right to left opposite to incident light direction)

So, let the distance of image will be v cm,

So

Here we see that v is positive so image will be formed in right side of lens (C’B’)