A lens has a power of +2.0 Dioptre, Which one of the following statements about the lens is true?
1
The lens is concave and has a focal length of 0.5 metre
2
The lens is convex and has a focal length of 2.0 metre
3
The lens is convex and has a focal length of 0.5 metre
4
The lens is concave and has a focal length of 2.0 metre