Option 1: The statement is correct. In a concave mirror, the radius of curvature is twice the focal length. This means that the mirror is curved inwards, and light rays that are parallel to the principal axis converge at the focal point.

Option 2: The statement is incorrect. The power of a convex lens is positive, indicating that it converges light rays. On the other hand, the power of a concave lens is negative, indicating that it diverges light rays.

Option 3: The statement is correct. A plane mirror has a flat surface, and its radius of curvature is considered to be infinity. Light rays incident on a plane mirror are reflected at the same angle as the angle of incidence, forming a virtual image.

Option 4: The statement is correct. According to Snell`s law, when a ray of light passes from an optically denser medium to an optically rarer medium, the angle of refraction is always less than the corresponding angle of incidence. This results in the bending of the light ray away from the normal.

Therefore, option 2 is the correct answer because the power of a convex lens is positive, not negative.