Diffraction interference patterns with phasor diagrams
https://www.youtube.com/watch?v=NazBRcMDOOo&
A wavefront is properly defined through the concept of phase difference: all points on a wavefront have zero phase difference.)
Pt source of light - as defined by HCV> this makes the Diffraction minimum.
4.14 Identical waves leaving two sources arrive at point P. Point P is 12 m from the first source and 16.5 m from the second. The waves from both sources have a wavelength of 3 m. State and explain what is observed at P.
The path difference is 16.5 − 12 = 4.5 m. Dividing by the wavelength, the path difference is equal to (1 + 1/2) × 3 m, i.e. it is a half-integral multiple of the wavelength. We thus have destructive interference
If the path difference is anything other than an integral or half-integral multiple of the wavelength, then the resultant amplitude of the wave at P will be some value between zero and 2A, where A is the amplitude of one of the waves (we are again assuming that the two waves have equal amplitudes). When sound waves from two sources interfere, points of constructive interference are points of high intensity of sound. Points of destructive interference are points of no sound at all. If the waves involved are light waves, constructive interference produces points of bright light, and destructive interference results in points of darkness. Complete destructive interference takes place only when the two waves have equal amplitudes.
A standing wave does not transfer energy: it consists of two traveling waves that transfer energy in opposite directions so the standing wave itself transfers no energy.
The complex can be understood in terms of the simple. The equation for SHM can be solved in terms of simple sine and cosine functions. These simple solutions help physicists to visualise how an oscillator behaves. Although real oscillations are very complex, a powerful mathematical machinery called Fourier analysis allows the decomposition of complex oscillations, sounds, noise and waves in general, in terms of sines and cosines. Energy exchange in oscillating electrical circuits is modelled using this type of analysis. Therefore the simple descriptions used in this topic can also be used in more complex problems as well.
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HCV Lecture Series
https://www.youtube.com/watch?v=RpOByUcmyOg&t=22s
Lec04: optics: From Diffraction to Interference by H C Verma
https://www.youtube.com/watch?v=-NCFy1ARPLI
Lec03: Optics : From One Medium to Another Refraction by H C Verma
https://www.youtube.com/watch?v=4oHdfdxFtvI
Lec02:Optics: From Fermat Principle to Reflection by H C Verma
https://www.youtube.com/watch?v=QHf_j3sM40c
Lec01 : Optics: From Shadows to Diffraction by H C Verma
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