Question

Two coherent sources of different intensities sound waves interfere. The ratio of maximum intensity to the minimum intensity is 25. The intensities of the sources are in the ratio:

• A. 25 : 1
• B. 5 : 1
• C. 9 : 4
• D. 25 : 16

Answer 1

The correct option is C 9 : 4

$\frac{I_{max}}{I_{min}}=\frac{25}{1}\left[\frac{A_1+A_2}{A_1-A_2}\right]=\frac{25}{1}\frac{A_1+A_2}{A_1-A_2}=\frac{5}{1}\frac{A_1}{A_2}=\frac{3}{2}\frac{I_1}{I_2}={\left(\frac{A_1}{A_2}\right)}^2=\frac{9}{4}$