Young's Double Slit Experiment: Practice Problem & Solution

Short Solution (Best for NEET):

To solve this problem, we apply the core principles of Young's Double Slit Experiment. Understanding the underlying formula is key to arriving at the correct answer below:

The maximum and minimum intensities are $I_{max} = (\sqrt{I_1} + \sqrt{I_2})^2$ and $I_{min} = (\sqrt{I_1} - \sqrt{I_2})^2$. Given $I_1/I_2 = n$, we can write $I_1 = n I_2$. The required ratio is $\frac{(\sqrt{n}+1)^2 - (\sqrt{n}-1)^2}{(\sqrt{n}+1)^2 + (\sqrt{n}-1)^2}$. Expanding the squares gives $\frac{4\sqrt{n}}{2(n+1)} = \frac{2\sqrt{n}}{n+1}$.