CBSE Class 7 Science Light
Properties of LightLight travels in straight lines, gets reflected by smooth reflecting surfaces and refracted by change in medium. Get introduced to spherical mirrors and lenses and learn how the images are formed due to reflection and refraction of light.
Reflection of LightThe process of sending back the light rays which falls on the surface of an object is known as reflection of light.
Laws of reflection 1: The incident ray, the reflected ray and the normal at the point of incidence, all lie in the same plane.
Laws of reflection 2: The angle of incidence is equal to the angle of reflection.
Lateral Inversion is the interchange of left and right side of an object as viewed in a plane mirror.
Spherical Mirrors: ConvexSpherical mirrors: Convex
Spherical Mirrors: ConcaveSpherical mirrors: Concave
Dispersion of LightThe phenomenon of splitting of white light into its constituent seven colours on passing through a glass prism is called dispersion of light.
Different colours undergo different deviations on passing through prism.
If a second identical prism is placed in an inverted position with respect to the first prism, all the seven colours recombine to form white light.
Rainbow is a natural spectrum appearing in the sky after a rain shower due to dispersion of light.