A lens has a focal length of -10 cm. What type of lens is it?

A lens has a focal length of -10 cm. What type of lens is it?

Step 1: Understand what focal length means. Focal length is the distance from the lens to the point where light rays converge or appear to diverge.
Step 2: Identify the sign of the focal length. A positive focal length indicates a converging lens (convex), while a negative focal length indicates a diverging lens (concave).
Step 3: Look at the given focal length, which is -10 cm. Since it is negative, it tells us something important about the lens.
Step 4: Conclude that because the focal length is negative, the lens must be a concave lens.

Focal Length – The distance from the lens to the focal point; negative values indicate a concave lens.
Types of Lenses – Concave lenses have negative focal lengths, while convex lenses have positive focal lengths.