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 […]
Ncert 12th Physics Chapter-10
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
Chapter-10|Wave Optics|NCERT 12th Physics: Diffraction of Light at a Single Slit: A parallel beam of light with a plane wavefront is made to fall on a single slit LN. As LN=a is of the order of wavelength of light, therefore diffraction occurs on passing through the slit. The wavelets from the single wavefront reach the
Chapter-10|Wave Optics|NCERT 12th Physics: Diffraction of Light: The phenomenon of bending of light around the sharp corners and the spreading of light within the geometrical Shadow of opaque obstacles is called diffraction of light. Diffraction is more when slit width ‘a’ is smaller than wavelength λ of the light.
Chapter-10|Wave Optics|NCERT 12th Physics: Young’s Double Slit Experiment: The fringes pattern(dark and bright fringes) shows that light has wave nature and bright fringes are result of constructive interference of the two light waves and dark fringes result due to destructive interferences. Let S₁ and S₂ are two very fine slits, at small distance d apart.
Chapter-10|Wave Optics|NCERT 12th Physics: Interference of Light Wave: Interference of light is the phenomenon of redistribution of light energy in a medium on account of superposition of light waves from two coherent sources. Constructive Interference: At the points where the resultant intensity of light is maximum, interference is said to be constructive. Destructive Interference: At
Chapter-10|Wave Optics|NCERT 12th Physics: Superposition Principle: When two or more waves travelling through a medium, superpose on each other, then a new wave is formed in which resultant displacement is equal to to the vector sum of displacement due to individual wave. Coherent Source of Light: Coherent source of light are those source of light
Chapter-10|Wave Optics|NCERT 12th Physics: Doppler’s Effect in Light: The change in frequency or wavelength of the light wave due to the relative motion between the light source and the observer is called Doppler’s Effect. Negative(-) sign indicates source is moving away from observer. When light source moving away from the observer, the frequency received by
Chapter-10|Wave Optics|NCERT 12th Physics: Proof For Law of Refraction at a Plane Surface(By Huygens’ Wave Theory): Let after t time a ray comes from B to D and cover a distance V₁t. Now we will form a wavelet at point D. Now, after t time a wave comes from A to C with speed V₂