Question

State with reason whether the following statements are

true or false.
The focal length of a concave lens is negative.​

Answer 1

For a diverging lens (for example a concave lens), the focal length is negative, and is the distance to the point from which a collimated beam appears to be diverging after passing through the lens. Determining the focal length of a concave lens is somewhat more difficult.

Answer 2

this is true.

hope it's helpful for you