Optical devices that form both real and virtual images for a real object are:
a. Concave mirror b. Convex mirror c. Concave lens d. Convex lens

Correct option is D

Correct Answer: (d)
Explanation
Let's examine each optical device:
· Concave mirror: Can form real images (when the object is beyond the focus} and virtual images (when the object is between the pole and focus}.
· Convex mirror: Always forms virtual, erect, and diminished images.
· Concave lens: Always forms virtual, erect, and diminished images.
· Convex lens: Can form real images (when the object is beyond the focal length} and virtual images (when the object is within the focal length}.
Therefore, the correct combination is Concave mirror and Convex lens.
Hence, the correct answer is Option (d}: a & d.
Additional Information