Chapter-9|Ray Optics and Optical Instrument|NCERT 12th Physics: Law of Refraction: First Law:- The incident ray, the refracted ray and the normal to the refracting surface at the point of incidence, all lie in the same plane. Second Law(Snell’s Law):- The ratio of the sine angle of incidence to the Sine angle of refraction is constant […]
Chapter-9|Ray Optics and Optical Instrument|NCERT 12th Physics: Refraction: The bending of light when it passes from one medium to another of different optical density is called refraction. When a beam of light encounters another transparent medium, a part of light gets reflected back into the first medium, while the rest enters the other. The direction
Chapter-9|Ray Optics and Optical Instrument|NCERT 12th Physics: Linear Magnification: The ratio of the height of the image(h´) formed by a spherical mirror to the height of the object(h) is called the linear magnification produced by the spherical mirror. It is denoted by m. m= h´/h
Chapter-9|Ray Optics and Optical Instrument|NCERT 12th Physics: Mirror Formula: We consider and object AB placed on the principal axis beyond the centre of curvature C of a concave mirror of small aperture. A ray AM from the object travels parallel to the principal axis and after reflection from the mirror it passes through focus F.
Chapter-9|Ray Optics and Optical Instrument|NCERT 12th Physics: Focal Length of Spherical Mirrors: We consider a ray AB parallel to principal axis, incident at point B of a spherical mirror(concave or convex) of small aperture. After reflection from the mirror, this ray converges to point F(in case of concave mirror) or appears to diverge from point
Chapter-9|Ray Optics and Optical Instrument|NCERT 12th Physics: Spherical Mirrors: A spherical mirror is a reflecting surface which forms part of a hollow sphere. (I) Concave Mirror (II) Convex Mirror (I) Concave Spherical Mirror: A spherical mirror whose reflecting surface is towards the centre or towards the inner hollow sphere is called concave spherical mirror. (II)
Chapter-9|Ray Optics and Optical Instrument|NCERT 12th Physics: Optics: It is the branch of Physics, which deals with the study of propagation of light. The subject of optics can be divided into two main branches. (I) Rays optics (II) Wave optics (I) Rays Optics(Geometrical Optics): It deals with practical nature of light and is based on
Chapter-10|Wave Optics|NCERT 12th Physics: Polarisation of Light by Scattering: From below figure the dots shows vibrations perpendicular to the plane of paper and double arrows show vibrations in the plane of paper. The electrons in the molecules begin to vibrate in both of these directions. The electrons vibrating parallel to the double arrows cannot send
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Chapter-10|Wave Optics|NCERT 12th Physics: Polarisation: A transverse wave or Light in which vibrations are present in all possible directions, in a plane perpendicular to the direction of propagation, is said to be unpolarised. If the vibrations of a wave are present in just one direction in a plane perpendicular to the direction of propagation, the
Chapter-10|Wave Optics|NCERT 12th Physics: Resolving Power of Optical Instruments: Resolving power of an optical instrument is the ability of the instrument to produce separate image of two close objects. According to Rayleigh, two point objects A and B will be just resolved, when Central maximum of diffraction pattern of B lies on first secondary minimum
