To obtain the same size image at $$2F_2$$ after refraction by a convex lens where should the object be placed?

When the object is placed at the centre of curvature of a lens then a ray of light AO which is parallel to the principal axis after refraction pass through the focus F along the direction OF. While the other ray AC pass through the opticl centre C and goes straight without any deviation. These two refracted light rays intersect each other at point A’, on the other side of the lens at the centre of curvature 2F. so, the image A’B’ formed in this case is at the centre of curvature, of same size as the object, real and inverted.