Question

If two light waves having same frequency have intensity ratio 4 : 1 and they interfere, the ratio of maximum to minimum intensity in the pattern will be

• A. 9 : 1
• B. 3 : 1
• C. 25 : 9
• D. 16 : 25

Answer 1

Answer: (A)

9 : 1

Answer 2

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