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Ray Optics and Optical Instruments
The refractive index of glass is 1.520 for red light and 1.525 for blue light. Let D1 and D2 be angles of minimum deviation for red and blue light respectively in a prism of this glass. then,
D1 < D2
D1 = D2
D1 can be less than or greater than D2 depending upon the angle of prism
D1 > D2
D.
D1 > D2
D = (μ - 1) A
For blue light μ is greater than that for red light, so D2 > D1
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Explain two advantages of a reflecting telescope over a refracting telescope.
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