Physics 9702 · AS & A Level · Photoelectric effect
Photoelectric effect — practice question
A beam of light with wavelength $\lambda$ falls on a metal surface whose work function energy is $\Phi$. The surface emits photoelectrons with maximum kinetic energy $E_{\text{MAX}}$.
(a)[2]
State an equation that links $\Phi$, $E_{\text{MAX}}$ and $\lambda$. Define any other symbols you use.
(b(i))[2]
Using your response to part (a), explain why the gradient of the line is independent of the metal surface.
(b(ii))[3]
Sodium has a work function energy of $2.28\,\text{eV}$. Find the minimum wavelength $\lambda_0$ for which $E_{\text{MAX}}$ is zero.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “The relation is $hc/\lambda = \phi + E_{max}$.” …