Concave Lens _ Image Formation

Ask yourself what happens to the rays leaving an object when they pass through a concave lens. Would they ever be brought together to form a real image?
There's your answer.

 

If two rays are, as you say, 'diverging' then how can they meet at a point to form a real image? They are surely getting further and further apart. No?

btw, what is a "virtual object"? (I missed that when I first read it).

 

However . . . . if you have a convex lens, producing a real image and you put a concave lens between the first lens and the image it forms, then the resulting (real) image will be formed a bit further away than the original (real) image.

 

You are talking of an intermediate image and not a virtual object here, I think.

In answer to your original question, I would say that you can produce a real or virtual image, depending on the focal lengths of the two lenses and the position.
A Galilean telescope has a convex lens with a concave eyepiece lens - producing a virtual image at a distance which you can actually focus you eye on. The optics inside some camera lenses produces a shifted real image because of the presence of a concave element. So there is no general rule.

 

Are you familiar with the thin-lens equation? If so, you can answer this question for yourself.