Question

The two interfering waves have intensities in the ratio 9 : 4. The ratio of intensities of maxima and minima in the interference pattern will be

• A. 1 : 25
• B. 25 : 1
• C. 9 : 4
• D. 4 : 9

Answer 1

Answer: (B)

25 : 1

Answer 2

$\frac{I_{\max}}{I_{\min} = \left( \frac{\sqrt{\frac{I_{1}}{I_{2}}} + 1}{\frac{\sqrt{I_{1}}}{\sqrt{I_{2}}} - 1} \right)^{2} = \left( \frac{\sqrt{\frac{9}{4}} + 1}{\sqrt{\frac{9}{4}} - 2} \right)^{2} = \frac{25}{1}}$