An equiconvex lens is prepared from a glass of refractive index 1.5. The radius of curvature of the surface is 0.5 m. The focal length of the lens is

Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres, corresponding to frequencies of 750–420 terahertz, between the infrared and the ultraviolet.