Photoelectric Effects and deBroglie Equation: Practice Problem & Solution

Solution Explained:

To solve this problem, we apply the core principles of Photoelectric Effects and deBroglie Equation. Understanding the underlying formula is key to arriving at the correct answer below:

The de Broglie wavelength of an electron is \(\lambda = \frac{1.227}{\sqrt{V}} \text{nm}\). Substituting \(V = 81 \text{V}\), we get \(\lambda = \frac{1.227}{9} \approx 0.136 \text{nm}\).