5. Modern Physics
Quantum Foundations — Quiz
Test your understanding of quantum foundations with 5 practice questions.
Practice Questions
Question 1
An electron is accelerated from rest through a potential difference of 150 V. What is its de Broglie wavelength?
Question 2
What is the peak wavelength $\lambda_{\max}$ of a blackbody at temperature $T=4000\,\mathrm{K}$?
Question 3
A metal has a work function $\phi=2.5\,\mathrm{eV}$ and is illuminated by light of wavelength $\lambda=400\,\mathrm{nm}$. What is the maximum kinetic energy $K_{\max}$ of the emitted electrons?
Question 4
What describes the 'ultraviolet catastrophe' predicted by classical physics for blackbody radiation?
Question 5
For frequencies with $h\nu\ll kT$, Planck’s spectral energy density $u(\nu)$ reduces to which expression?