The light intensity incident on a metallic surface produces photoelectrons with a maximum kinetic energy of 2 eV. The light intensity is doubled. Determine the maximum kinetic energy of the photoelectrons (in eV).
A) 4
B) 2
D) 3
E) 16

Question

The light intensity incident on a metallic surface produces photoelectrons with a maximum kinetic energy of 2 eV. The light intensity is doubled. Determine the maximum kinetic energy of the photoelectrons (in eV).
A) 4 
B) 2 
D) 3 
E) 16

Quizplus · Accepted Answer

The maximum kinetic energy of photoelectrons is independent of the intensity of light, according to the photoelectric effect equation $E_{\rm max}=hf-\phi$, where $f$ is the frequency of the incident light and $\phi$ is the work function of the metal. Therefore, doubling the intensity of light does not change the maximum kinetic energy of photoelectrons.

The Light Intensity Incident on a Metallic Surface Produces Photoelectrons