Problem 5 - Entrance Test

What is the de Broglie wavelength of an electron with kinetic energy K?

A. h / √(2mK)B. √(2mK) / hC. hK / √(2m)D. h / (2mK)

Correct: A

The de Broglie wavelength is λ = h/p, where p is the momentum. Kinetic energy K = p²/2m, so p = √(2mK). Therefore, λ = h/√(2mK).