Question

A thin lens produces an image of the same size as the object. Then from the optical centre of the lens, the distance of the object is

• A. zero
• B. $4f$
• C. $2f$
• D. $f/2$

Answer 1

The correct option is C $2f$

By the given problem, a thin lens produce an image of the same size as the object.

We know, if the object is placed perpendicular to to the principal axis of the convex lens at a distance $2f$ from the optical centre of the lens, the image is formed on the other side of the lens as the object at a distance $2f$ from the lens. This image is real, inverted and equal in size to the object.

So, for the given question, distance of the object from the optical centre of the lens will be $2f$.

So, the correct answer is - (C) $2f$