Question

The intensity ratio of two waves is 9 : 1. These wave produce interference. The ratio of maximum intensity to minimum intensity will be

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

Answer 1

The correct option is D 4 : 1

$\frac{I_1}{I_2}=9$
$\frac{I_{max}}{I_{min}}={\left(\frac{\sqrt{\frac{I_1}{I_2}}+1}{\sqrt{\frac{I_1}{I_2}}-1}\right)}^2={\left(\frac{3+1}{3-1}\right)}^2=4$