Which type of lens produces an upright image?

• A. Concave lens
• B. Convex lens
• C. Plane lens
• D. Spherical lens

Answer: (A)

A diverging (concave) lens spreads light rays outward. When you trace those rays backward, they appear to come from a point on the same side of the lens as the object, forming a virtual image that is upright and smaller than the object. Because this kind of lens always produces an upright image, it’s the best answer. A convex lens can produce upright images only in specific cases (when the object is very close to the lens), but not always. A plane surface doesn’t create a real optical image in the same sense, and a spherical lens is just a general term for curved lenses that can produce different orientations depending on arrangement.