Which statement correctly describes a convex lens?

Which statement correctly describes a convex lens?

• A. It is thicker in the middle than at the edges, and converges light.
• B. It is thinner in the middle than at the edges, and diverges light.
• C. It is thicker at the edges and diverges light.
• D. It is thinner in the middle and converges light.

Answer: (A)

Convex lenses are thicker in the middle than at the edges. That outward bulge causes light rays that pass through to bend toward the optical axis, so parallel rays converge to a focal point on the other side. That combination—middle thickness and convergence of light—is what defines a convex lens. In contrast, a lens that is thinner in the middle (concave) bends rays outward, causing divergence, which is why those descriptions describe a different type of lens.

Convex lenses are thicker in the middle than at the edges. That outward bulge causes light rays that pass through to bend toward the optical axis, so parallel rays converge to a focal point on the other side. That combination—middle thickness and convergence of light—is what defines a convex lens. In contrast, a lens that is thinner in the middle (concave) bends rays outward, causing divergence, which is why those descriptions describe a different type of lens.