Young's Double Slit Experiment: Practice Problem & Solution

Solution Explained:

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:

When the chamber is evacuated, the refractive index decreases (from $\mu_{air}$ to 1). The wavelength of light $\lambda = \lambda_0/\mu$ increases. Since fringe width $\beta = \frac{\lambda D}{d}$, an increase in wavelength leads to a larger fringe width.