An object is placed at a distance equal to 2f in front of a convex lens. Draw a labelled ray diagram to show the formation of image. State two characteristics of the image formed.

Formation of image when an object is placed at a distance equal to $2f$ in front of a convex lens: 

Two characteristics of the image formed are:

1. Nature of image $-$ real and inverted.

2. Size of Image $-$ same size as that of the object.

Explanation

When an object is at the focus $(2F')$ of a convex lens, which means the object is at a distance equal to twice the focal length, $2f$ of a convex lens, the image formed is real, inverted, same size as the object, and at a distance $2f$ on the other side of the lens.