Question

An image formed by a ________ lens cannot be obtained on a screen.

Answer 1

1. A real image occurs where rays converge, whereas a virtual image occurs where rays only appear to diverge
2. Concave lenses create only virtual images. After the rays are refracted, they never converge and so there will be no real images.
3. All the images formed by a concave lens will be upright, virtual, and diminished.

Hence, an image formed by a concave lens cannot be obtained on a screen.