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

23784 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

A space probe of mass 1000kg, moving at 200m/s, explosively ejects a capsule of mass 300kg. The speed of the probe after the explosion is 250m/s. What is the velocity of the capsule?


What is the most effective use of the equation sheet?


A pellet of mass 8.8 g embeds itself in a wooden block of 450 g which is suspended by a light in-extensible string. After the collision the block reaches a max height of 0.63 m. Calculate the initial velocity of the pellet.


Explain why an object moving around a circle is said to be accelerating when it has no resultant force acting upon it.


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:

© 2025 by IXL Learning