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:

de Broglie wavelength is \(lambda = \frac{h}{\sqrt{2mK}}\). If \(K' = 16K\), then \(lambda' = \frac{\lambda}{\sqrt{16}} = \frac{\lambda}{4}\). The percentage decrease is \(\frac{\lambda - \lambda/4}{\lambda} \times 100% = 75%\).