Question

how is the image formed when the object is kept at the focus in a concave mirror . The rays are parallel and dont converge right ?​

Answer 1

Answer:

No image is formed.

Light rays reflected from the mirror neither converge (forming a real image) nor diverge (allowing a virtual image to be seen).

Light rays from any point on the object are reflected so that they are parallel to each other. It’s simply the reverse case of parallel light rays hitting the mirror and forming an image at the principal focus.

When the object is placed at the focus the image is formed at infinity & highly enlarged.