What happens when an object is moved at a constant speed from infinity to focus of a concave mirror?

1. A

   Always real and speed of image continuously increases

2. B

   Always real and speed is initially smaller and finally larger than object speed

3. C

   Initially real and moving with speed smaller than object speed but later on image becomes virtual and moving with speed of object

4. D

   Always virtual and speed is less than object speed

As the object moves from infinity to centre of curvature, the image formed by a concave mirror would be real and is moving from focus to centre of curvature, but as the object crosses centre of curvature and moves towards focus the image is still real but moves from centre of curvature towards infinity and when the object is at focus the real image would be formed at infinity. So, image speed is smaller in beginning when the object is moving from infinity to centre of curvature and increases thereafter.