Question

distance between the middle of the lens and the focal point is called the

○ focal point

○ focal length

○ optical center

○ convex lens

Explanation:

The question is about the terminology related to a lens in physics (a subfield of Natural Science). The focal length is defined as the distance between the middle (optical center) of a lens and its focal point. The other options: Focal Point is the point itself, Optical Center is the middle of the lens, and Convex Lens is a type of lens, not a distance.

Answer:

B. Focal Length