Physics - The Photoelectric Effect
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Flashcards
What is the photoelectric effect?
The release of an electron when a photon is incident on a metal surface.
When does the photoelectric effect occur?
When the photons incident on a material have a frequence above a threshold frequence $f _ 0$.
Why was the discovery of the photoelectric effect significant?
It showed that light was a particle as well as a wave.
2021-06-06
What is the atomic structure of a metal?
A lattice of positive ions surrounded by a sea of free electrons.
What is tthe work function?
THe minimum energy required to remove an electron from the surface of a metal.
What is the threshold frequency?
The minimum frequency of light required to produce photoelectrons from a metal.
What is monochromatic light?
Light of a single frequency/wavelength.
What is the relationship between the work function $\phi$ and the threshold frequency $f _ 0$?
What is required for a photon to be able to produce photoelectrons?
Its frequency is greater than the threshold frequency.
Why can’t light sources below the threshold frequency produce photoelectrons?
The photon energy is less than the work function.
What effect does increasing the frequency of light have on photoelectrons?
The photoelectrons will have a greater max kinetic energy.
What is the effect of increasing the intensity of light on photoelectrons?
More photoelectrons will be produced but they will have the same max kinetic energy.
Why does the kinetic energy of photoelectrons from light vary in the photoelectric effect?
Some electrons are deeper into the metal and require more energy to be liberated.
What two factors determine the maximum kinetic energy of photoelectrons?
- The frequency of the light
- The work function of the mtal
What determines the energy delivered by a wave?
The intensity of the wave.
What is Einstein’s photoelectric equation?
What does $E$ mean in Einstein’s photoelectric equation?
The energy coming into a metal.
What does the work function, $\phi$, mean in Einstein’s photoelectric equation?
The minimum energy required to release an electron.
What does the maximum kinetic energy, $KE _ {\text{max}}$, mean in Einstein’s photoelectric equation?
The energy leftover that is given to an electron.
What’s another way of writing Einstein’s photoelectric equation that shows the frequency of the light coming into a metal?
What is the work function, $\phi$, equal to in Einstein’s photoelectric equation?
What is the $KE _ \text{max}$ equal to in Einstein’s photoelectric equation?
What is the stopping potential?
The potential required for stopping the removal of an electron in the Photoelectric effect.
What is the relationship between stopping potential $V _ s$ and the $KE _ \text{max}$ of an electron in Einstein’s photoelectric equation?
2022-06-04
![PHOTO CONFUSING CIRCUIT] This is a setup used to find the max kinetic energy of emitted photoelectrons. Why does the current decrease as the voltage produced by the variable power supply is increased?
Because the emitted electrons are having to do work against the electric field.