When an object is in F and F2 of a convex lens. So, we need to place the object between 20 and 40 cm of the lens.

When an object is placed between F and 0 of a convex lens, its magnified, vertical and visible image is formed across the FL i.e. on the same side of the lens.

 So for this, we need to place the object at a distance of less than 20 cm from the lens.