Will you get a point image if you place a paper at the focal point ?

Why don't you get an image for certain object distances ?

What happens if you hold the paper at a distance shorter thant the focal length from the mirror and move it away ?

Two point surces S_(1) and S_(2) are 24 cm apart. Where should a convex lens of focal length 9 cm be placed them , so that the images of both sources are formed at the same place ?

If you throw a paper bowl into water.

Draw a ray diagram to locate the position of image when a point source (S) is placed on optical axis Mn of a convex lens, in such a way that it is beyond focal point (F). See figure.