Two lenses having f1:F2=2:3 has combination to make no dispersion.Find the ratio of their dispersive power?a)2:3 b)3:2 c)4:9 d)9:4​

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Two lenses having f1:F2=2:3 has combination to make no dispersion.Find the ratio of their dispersive power?a)2:3 b)3:2 c)4:9 d)9:4​

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Khải Quang 5 years 2021-07-14T05:39:42+00:00 1 Answers 88 views 0

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  1. minhkhoi
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    2021-07-14T05:41:35+00:00
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    Answer:

    b)3:2

    Explanation:

    The dispersive power is the reciprocal of the focal length:

    P=\frac{1}{f}

    Given the ratio of focal lengths:

    \frac{f_1}{f_2} = \frac{2}{3}\\\\\frac{\frac{1}{P_1}}{\frac{1}{P_2}}=\frac{2}{3}\\\\\frac{P_2}{P_1}=\frac{2}{3}\\\\\frac{P_1}{P_2}=\frac{3}{2}

    Therefore,

    P₁ : P₂ = 3 : 2

    Hence, the correct option is:

    b)3:2

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