Question
Two coherent sources, whose intensity ratio is $81: 1$, produce interference fringes. Calculate the ratio of the intensities of maxima and minima in the fringe system.
✓
Answer
Data $: l_1: l_2=81: 1$
If $E_{10}$ and $E_{20}$ are the amplitudes of the interfering waves.
the ratio of the maximum intensity to the minimum intensity in the fringe system is
$\therefore r =\sqrt{\frac{l_4}{l_2}}=\sqrt{81}=9$
$\therefore \frac{l_{\max }}{l_{\min }}-\left(\frac{9+1}{9-1}\right)^2-\left(\frac{10}{8}\right)^2-\left(\frac{5}{4}\right)^2-\frac{25}{16}$
If $E_{10}$ and $E_{20}$ are the amplitudes of the interfering waves.
the ratio of the maximum intensity to the minimum intensity in the fringe system is
$\therefore r =\sqrt{\frac{l_4}{l_2}}=\sqrt{81}=9$
$\therefore \frac{l_{\max }}{l_{\min }}-\left(\frac{9+1}{9-1}\right)^2-\left(\frac{10}{8}\right)^2-\left(\frac{5}{4}\right)^2-\frac{25}{16}$
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