Where is the focal point for a concave lens located?

• A. In the center of the lens
• B. Beyond the lens on the far side
• C. On the same side as the light source
• D. On the opposite side of the lens from the light source

Answer: (C)

For a concave (diverging) lens, the light rays bend outward as they pass through, so they don’t actually converge to a real point on the far side. Instead, if you extend the refracted rays backward, they appear to originate from a point on the same side as the light source. That virtual focal point lies on the object’s side of the lens, and the focal length is considered negative in standard sign convention. So the focal point being on the same side as the light source is the correct description.