Converging Lens Focuses Parallel Rays

Steps:

• Recall that a converging lens bends parallel light rays inward toward a focal point on the opposite side.
• Identify diagrams where incoming parallel rays meet at a single point after passing through the lens.
• Eliminate options showing rays diverging, remaining parallel, or converging before the lens.
• Select the diagram matching this convergence pattern.

Why D is correct:

• It depicts parallel rays refracting through the lens and converging at the focal point, consistent with the lensmaker's formula where positive focal length $f$ focuses collimated light.

Why the others are wrong:

• A: Shows rays diverging outward, characteristic of a diverging lens.
• B: Rays remain parallel after the lens, indicating no refraction occurs.
• C: Rays converge to a point before the lens, violating the focal point location for parallel incident light.

Final answer: D