Question

The ratio of maximum and minimum intensities of two sources is $4:1.$ The ratio of their amplitudes would be –

• A. $1:3$
• B. $3:1$
• C. $1:9$
• D. $1:1$

Answer 1

Answer: (B)

$\frac{I_{max}}{I_{min}}=\frac{4}{1}$
Intensity is directly propotional to square of amplitude. $\Rightarrow \frac{A_{max}}{A_{min}}=\frac{2}{1}\Rightarrow \frac{A_1+A_2}{A_1-A_2}=\frac{2}{1}$
$\Rightarrow \frac{A_1}{A_2}=\frac{3}{1}$ .