Скачать с ютуб Refraction through prism class 10 | 10th class physics | punjab, federal, kpk, balochistan board в хорошем качестве

Refraction through prism class 10 | 10th class physics | punjab, federal, kpk, balochistan board

Refraction through prism in urdu hindi 10th class physics wallah chapter 12 Applications of total Internal refelction TIR. Refraction of light. Prism. 12.7 REFRACTION THROUGH PRISM Prism is a transparent object (made of optical glass) with at least two polished plane faces inclined towards each other from which light is refracted. In case of triangular prism (Fig.12.17), the emergent ray is not parallel to the incident ray. It is deviated by the prism from its original path. The incident ray PE makes an angle of incidenace ‘i’ at point E and is refracted towards the normal N as EF. The refracted ray EF makes an angle ‘r’ inside the prism and travels to the other face of the prism. This ray emerges out from prism at point F making an angle ‘e’. Hence the emerging ray FS is not parallel to the incident ray PE but is deviated by an angle D which is called angle of deviation. 12.8 LENSES A lens is any transparent mat 12.4 REFRACTION OF LIGHT If we dip one end of a pencil or some other object into water at an angle to the surface, the submerged part looks bent as shown in Fig.12.7. Its image is displaced because the light coming from the underwater portion of the object changes direction as it leaves the water. This bending of light as it passes from one transparent medium into another is called refraction. Refraction of light can be explained with the help of Fig.12.8. A ray of light IO travelling from air falls on the surface of a glass block. Fig. 12.8: Refraction of light by a glass block At the air-glass interface, the ray of light IO changes direction and bends towards the normal and travels along the path OR inside the glass block. The rays and OR are called the incident ray and IO the refracted ray respectively. The angle ‘i’ made by the incid SUMMARY  When light travelling in a certain medium falls on the surface of another medium, a part of it turns back in the same medium. This is called reflection of light. There are two laws of reflection: i. The incident ray, the reflected ray, and the normal all lie in the same plane. ii. The angle of incidence is equal to the angle of reflection (i.e., i = r).  Like plane surfaces, spherical surfaces also reflect light satisfying the two laws of reflection.  In mirrors, image formation takes place through reflection of light while in lenses image is formed through refraction of light.  The equation relating the distance of the object p from the mirror/lens, distance of the image q and the focal length f of the mirror/lens is called mirror/lens formula, given by  Magnification of a spherical mirror or thin lens is defined as “the ratio of the image height to the object height.” i.e.,  Power of a lens is defined as “the reciprocal of its focal length in metres”. Thus Power of a lens = P = 1 / focal length in metres. The SI unit of power of a lens is “Dioptre”, -1 denoted by a symbol D. If is expressed in metres so that 1 D = 1 m . Thus, 1 Dioptre f is the power of a lens whose focal length is 1 metre.  The refractive index ‘n’ of a material is the ratio of the speed of light ‘c’ in air to the speed of light ‘v’ in the material, thus  The bending of light from its straight path as it passes from one medium into another is called refraction.  Refraction of light takes place under two laws called laws of refraction. These are stated as: i. The incident ray, the refracted ray, and the normal at the point of incidence The ratio of the sine of the angle of incidence ‘i’ to the sine of the angle of refraction ‘r’ is always equal to a constant i.e., = constant. where the ratio is equal to the refractive index of the second medium with respect to the first medium. i.e., This is also called Snell's law. .  o The angle of incidence for which the angle of refraction becomes 90 is called critical angle. When the angle of incidence becomes larger than the critical angle, no refraction occurs. The entire light is reflected back into the denser medium. This is known as total internal reflection of light.  A simple microscope, also known as a magnifying glass, is a convex lens which is used to produce magnified images of small objects.  A compound microscope is used to investigate structure of small objects and has two converging lens, the objective and the eyepiece.  Telescope is an optical instrument which is used to observe distant objects using lenses or mirrors. A telescope that uses two converging lenses is called refracting telescope. A telescope in which the objective lens is replaced by a concave mirror is called reflecting power telescope.  The magnifying power is defined as “the ratio of the distinct images of distant objects on its retina is known as nearsightedness. The nearsighted eye can be corrected with glass or contact lenses that use diverging lenses Light rays from the distant objects will . diverge refracts the light rays more towards t