In the photoelectric effect, what happens as you increase the frequency of light keeping the same intensity constant?

E=hf, so as you increase the frequency of light, the energy of each photon hitting the metal surface is greater. Thus the electrons liberated from the surface of the metal have a greater maximum kinetic energy.
We also said that the intensity of the light should stay the same. Intensity = Power/Area = (Energy/time)/Area. Given that the energy of each photon is greater with a higher frequency of light, there must be fewer photons hitting the metal surface per unit time in order to keep the intensity constant.
Thus, assuming that initially the photon frequency was above the threshold frequency, increasing the frequency at the same intensity will increase the kinetic energy of the photoelectrons liberated from the metal surface, but also reduce the number of electrons released.

AJ
Answered by Alexander J. Physics tutor

26770 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

A ball of mass m is thrown from the ground at the speed u=10ms^-1 at an angle of 30 degrees. Find the max height, the total flight time and the max distance it travels?Assume g=10ms^-1 and there is no air friction


What does the photoelectric effect demonstrate?


A passenger is standing in a train. The train accelerates and the passenger falls backwards. Use Newton's first law of motion to explain why he fell backwards.


What is dimensional analysis and how is it used?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning