How does the image distance (di) of a convex lens compare with the image distance of a concave lens? a. the image distance of the convex lens is positive, and that of the concave lens is negative. b. both are negative for a virtual image. c. both are positive for a virtual image d. the image distance of the convex lens is negative, and that of the concave lens is positive.

Explanation:

Image distance of a mirror is defined as the distance between the optical center and the formed image.

The image formed by a concave lens is virtual always. We can say that the image distance for a concave lens is negative. The convex lens or the converging lens can form both real and virtual images. So, the image distance  for a convex lens can be either positive or negative. Generally, the image distance for convex lens is positive.

So, the correct option is (a) "  The image distance of the convex lens is positive, and that of the concave lens is negative ".