Question:
Two coherent light sources having intensity in the ratio $2 \times$ produce an interference
pattern. The ratio $\frac{I_{\max }-I_{\min }}{I_{\max }+I_{\min }}$ will be :
Correct Option: , 3
Solution:
(3)
Let $I_{1}=2 x$
$I_{2}=1$
$I_{\max }=\left(\sqrt{I_{1}}+\sqrt{I_{2}}\right)^{2}$
$I_{\min }=\left(\sqrt{I_{1}}-\sqrt{I_{2}}\right)^{2}$
$\frac{I_{\max }-I_{\min }}{I_{\max }+I_{\min }}=\frac{(\sqrt{2 x}+1)^{2}-(\sqrt{2 x}-1)^{2}}{(\sqrt{2 x}+1)^{2}+(\sqrt{2 x}-1)^{2}}$
$=\frac{4 \sqrt{2 x}}{2+4 x}=\frac{2 \sqrt{2 x}}{1+2 x}$
Click here to get exam-ready with eSaral
For making your preparation journey smoother of JEE, NEET and Class 8 to 10, grab our app now.