Interference In Thin Films
Notes
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See all →- What are the conditions for bright and dark fringes in reflected light from a thin film? In one line In reflected light from a thin film, brightness occurs when 2μ tcos r = (2n-1)λ/2 and darkness when 2μ tcos r = nλ . Explained s... 1
- How does interference occur in a thin film of uniform thickness, and what is the path difference? In one line Light reflected from the top and bottom surfaces of a thin film comes from the same wave (division of amplitude), so the two ref... 1
- How are interference fringes formed in a wedge-shaped thin film and what is the fringe width? In one line A wedge-shaped film has thickness increasing steadily from the edge, so each fringe follows a line of constant thickness, giving... 1
- How are Newton's rings formed and why is the central spot dark in reflected light? In one line Newton's rings are concentric circular fringes formed by interference in the air film between a plano-convex lens and a flat gla... 1
- How are Newton's rings used to find the wavelength of monochromatic light? In one line By measuring the diameters of two dark rings that are p rings apart and knowing the lens radius R , the wavelength is found from... 1
- How are Newton's rings used to find the refractive index of a transparent liquid? In one line Filling the gap between the lens and plate with a liquid shrinks the rings by a factor √(μ) , so the refractive index is the rat... 1