Question

Two waves have their amplitudes in the ratio $1:9$ .The maximum and minimum intensities when they interfere are in the ratio

• A. $\frac{25}{16}$
• B. $\frac{16}{26}$
• C. $\frac{I}{9}$
• D. $\frac{9}{1}$

Answer 1

Answer: (A)

$\frac{25}{16}$

$\frac{I_{max}}{I_{min}}={\left(\frac{\frac{a_1}{a_2}+1}{\frac{a_1}{a_2}-1}\right)}^2$

$={\left(\frac{\frac{1}{9}+1}{\frac{1}{9}-1}\right)}^2$

$={\left(\frac{5}{4}\right)}^2=\frac{25}{16}$