When interference between thin films occurs, the path difference between two interfering rays is 2t. If 'n' is the refractive index of the medium, the bright circles are obtained when _ with m = 0, 1, 2, 3, ...
Correct answer: A. (2m + 1) λ = 4nt
- A. (2m + 1) λ = 4nt
- B. (2m + 1) λ = 2nt
- C. 2m = nt
- D. mλ = 2nt
Explanation
The explanation is given below:In thin film interference, bright circles would occur by constructive interference. Constructive interference is given by:2t = (m+½)λn, m = 0,1,2,3,...4t = (2m+1)λnt is the thickness of the medium.λn is the wavelength of light in the medium.λn = λ/nTherefore, for constructive interference:(2m + 1)λ = 4nt, m = 0,1,2,3,...n is the refractive index of the medium.
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Light is studied through reflection, refraction, dispersion, interference, diffraction and polarization, linking ray behavior with its wave nature. Questions may involve mirrors, lenses, optical instruments, refractive index and image formation, while geometrical optics deals with rays and wave optics explains effects such as interference and diffraction.
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