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A diffraction grating with 10^6 lines /m is used to determine the wavelengthof a monochromatic source. the angle of first order diffraction is 30 degree . The wavelength of the source is ? options: a) 1000 nm b) 500 nm c) 400 nm d) 600 nm |
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Answer» Answer Diffraction GRATING: d sinθn = nλ where N is an integer λ=5.30×10−7m When n = 1, θ1 = 15.4° Slit SEPARATION, d = sinθ1λ = sin15.4o5.30×10−7 = 1.996×10−6m When n =2 slit separation d = sinθ2λ ⟹sinθ2=dλ ⟹θo=sin−1(1.996×10−65.30×10−7) ⟹θ2=16.7o |
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