Rays from the sun converge at a point 25 cm behind a convex lens. The distance at which an object be placed in front of the lens to get a virtual image, is:

Hint

Recall the properties of convex lenses and the conditions for forming virtual images.

Quick oral answer

To get a virtual image, the object must be placed between the lens and the focus. Since the focal length is 25 cm, the object must be placed more than 50 cm away from the lens.