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

27638 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

What is the derivative of distance with respect to time.


From the definition of the decay constant for nuclear decay, derive the exponential decay equation.


Outline the principal features of a geostationary orbit and use them to explain one use of satellites in this type of orbit.


The radius of the Earth is 6,400km and has a mass of 6x10^24kg. Calculate the minimum velocity needed by a projectile, fired from the surface of the Earth in order to escape the Earths gravity.


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