Question

The ratio of intensities of two waves is 9 : 1. They are producing interference. The ratio of maximum and minimum intensities will be.

• A. 10 : 8
• B. 9 : 1
• C. 4 : 1
• D. 2 : 1

Answer 1

Answer: (C)

4 : 1

Answer 2

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