I understand that electrons can be released from a material, such as metal, through the photoelectric effect. I also understand that some of them might "re-attach" themselves to the metal. For practical uses, it sounds like the electrons would be re-captured in some way, but for the electrons...
Assume that a light shining on a metal initially resulted in electrons being emitted from the surface of the metal due to the photoelectric effect. If the light is left on indefinitely, will the emission of electrons eventually cease? (Assume the metal is insulated on all surfaces apart from the...
Homework Statement
In photoelectric effect I-V graphs, for the same intensity but with different light frequencies (f2>f1), the I-V graph has the same max photocurrent but |Vs2| > |Vs1|. If we concentrate between the cutoff and the saturation regions of the I-V graph, we can see that at any...
Homework Statement
If blue and red light are used on a photoelectric cell and they both have the same intensity (Power per area). Choose the correct option from the following
Homework Equations
E = nhf
Intensity = power/area
Quantum effeciency = 100%
The Attempt at a Solution
if they have...
Homework Statement
Photons with momentum p= 7.88 x 10-18 strike a photoelectric material which is in the configuration shown in the figure. The cutoff voltage is measured to be Vstop= 1.75 V. What is the work function of the photoelectric material?
Homework Equations
p = Ephoton / c
E0 = (c...
In the experiment of the determination of ##h## using the photoelectric effect produced by light emitted by led's there is the systematic problem of the "dark current" or "back current", i.e. the current caused by photoelectric effect on the anode of the system which is used in the expreriment...
The photoelectric effect is usually presented as an example disproving classical electromagnetism as viable model for interaction of light with matter and as evidence of quantization of energy in the electromagnetic field, i.e. the existence of photons. I would like to discuss a thought based on...
During the photoelectric process, photons are absorbed and electrons are ejected. In Compton scattering, photons are scattered rather than absorbed. My textbook (Quantum Physics of Atoms,Molecules,Solids,Nuclei, and Particles) explains that absorption occurs in the photoelectric process because...
Homework Statement
X·ray is produced when an electron is incident on a metal surface with ##2x10^8 ms^-1## velocity
.Applying this X-ray on the surface of two metals having work function of 5 eV and 2.3eV, photoelectric effect is observed.
e by
Homework Equations
The Attempt at a Solution...
Hi all,
With the photoelectric effect is it the 'sea' of free electrons that are ejected if the photons are above threshold frequency (i.e. Conduction band electrons ) rather than valence electrons ? If say very energetic gammas are used then suppose this could knock out valence electrons but...
When the emitter is connected to the positive polarity of a battery, it is said that 'Some high speed electrons are still able to reach the collector and therefore there is flow of current.'
(1) What is the flow of electrons like in this case?
I thought electrons are supposed to flow from...
my son did a duality of light science fair project .. did tons of work.. still likes doing the experiments at home
anyway.. first off his wool and ebonite rod stopped putting a static charge on his christmas tree tinsle that he has on the end of a piece of a metal hanger sticking out of a metal...
According to the equation, the graph of kinetic energy of emitted photoelectrons from a metal vs the frequency of incident radiation gives a straight line.
My doubt is, what factors does the slope of this line depend on? I think it depends on the nature of metal used. Correct me if I am wrong.
Homework Statement
Light illuminates a metallic surface with work function of 1.20 eV. It takes 1.0 V of retarding potential to stop all of the photoelectrons from reaching the opposite plate. Find the maximum speed of the photoelectrons.
Homework Equations
hf = w
hf = w + Ek
The Attempt at...
Hey, I've being studying the Photoelectric effect, I think I understand it superficially. One thing that has been bugging me is this:
"Given that it is possible to move electrons with light and given that the energy in a beam of light is related to its intensity, classical physics would predict...
What properties of waves caused the photoelectric effect to indicate the fact that light was quantized. Why couldn't it be explained by light waves being emitted at the same frequency. I am a little confused about why light couldn't still be a wave. Couldn't the photoelectric effect be explained...
I think that an electron only absorb a photon with energy corresponding to the energy levels in an atom.
If the energy of a photon is higher than the energy between a specific energy level and infinity level (0 eV), it can also absorb the photon and the remained energy is changed to KE.
Am I...
A few quick questions I'd like cleared up:1) Alkali metals are said to have a really low threshold energy, enough for visible light to cause the photoelectric effect. Does this mean if I aim a flashlight (turned on) at a piece of sodium, I could ionise it? Simply flashing a light over a piece of...
This isn't really a homework question but I do have to know it for my lab report so I figure this is a good place to post it. So for my lab we had the setup that is displayed in the picture attachments. My question deals specifically with step #9 of the lab instructions. I'm assuming that the...
I've read that the photoelectric effect cannot be explained according to Maxwell's equations and theory of electromagnetism. Classical EM theory treats light as a wave and states that the intensity of the light matters and not the frequency. According to Einstein, if we think of light as a...
I have studied photoelectric effect. I have many doubts regarding that, so firstly, I cannot understand when, THRESHOLD FREQUENCY arises. " Threshold frequency is the frequency at which the electron gets ejected from the electrode & runs toward the other negatively charged electrode " , so my...
Hey I have a doubt that when on a metal surface photon falls then electrons are ripped off if the photon has frequency equal to or more than threshold frequency but photon falling on electron has a downward momentum and elctron rips off in a upward momentum...how is it possible according to law...
question is based on the video above (1.5 mins).
The main question is this, if photoelectrons are released based on the frequency of light that hits it, why is it that there is a large difference on the multimeter between when there is no filter, and when the blue filter is used (small...
I've a doubt regarding photoelectric effect. It's said that photoelectric effect is proof for light to be a particle. But, when seen into the theory, relations between wavelength and kinetic energy, frequency and photoelectric current are explained. The means we have used wave characters like...
Homework Statement
Hi everybody! I just did the photoelectric experiment this week, and I have a report to write about it. We used a mercury vapour lamp, a set of metal interference filters and a grey filter in order to find the intersection point (and therefore ##U_{g,max}## between the...
Homework Statement
In a photoelectric experiment, a stopping potential of 2.70 eV is measured when ultraviolet light of wavelength 380 nm is incident on the metal. If blue light of wavelength 440 nm is used, what is the new stopping potential in eV?
Homework EquationsThe Attempt at a...
Homework Statement
A metal surface had dimensions of 1.5mm x 2mm. The intensity of light incident on surface is 4.5×10^-6 W/m^2. On average one electron is emitted for every 300 photons incident on the surface. Determine the initial current leaving the metal.
●wavelength of light incident is...
I know the definition of photoelectric effect : the release of electrons from a metal when it is in contact with electromagnetic waves..
However, my question is.. If a light wave hits a metal and that photon has freq = threshold frequency of that metal, does this mean that the energy of the...
Guys I'm understand this effect but understanding it i got a practical doubt that though the bond(metallic bond) between metal atoms is very strong then too electrons are easily ripped of compared to other elements
I know metals have free electrons but they are strongly bonded to the atoms then...
I understand the concepts of photoelectric effect where an electron will be emitted when a photon with sufficient energy collides with it.
There are two parts to this question,
1. What happens during the collision?
Is the photon absorbed by the photoelectron wholly as energy?
2. If so...
My question is about the experiment in which detectors are used behind the slits to determine which slit the photon goes through. Specifically, it's about the detectors themselves. What I found is that these detectors are some kind of photoelectric detectors. My question is this. During the...
Since the binding energy of an electron in outer shell is smaller than the binding energy of the electron in inner shell, why the photon kick out the electron orbiting in inner shell? It is always easier to kick out the electron with less binding energy, is it not?
I had this question popped into my mind when I was reading this topic one day.
In the photoelectric experiment, when light, having frequency greater than the threshold frequency, falls on a metal, electrons are emitted. Since electrons emitted are of different energies (I presume it's because...
Hi. I'm high school student who is doing a math project.
Yesterday, my project partner (to be precise, his teacher) told me that one can
prove the photoelectric effect with conic section, especially with hyperbola.
(But, actually, I can't even understand the meaning of the statement. For me...
Given an experiment of the photoelectric effect, if we keep the intensity of the shining light source constant, by increasing the frequency of the light, the number of ejected electrons from the metal surface "decreases". I understand that increasing frequency (assuming it is already higher than...
Homework Statement
We are performing a lab on the photoelectric effect tomorrow and have some pre-lab questions.
1: If an electron must use an energy equal to the work function of the phototube cathode, in order to escape the cathode's surface, how much kinetic energy does it have once it...
Hello everyone, thanks for reading
I'll explain my question. At first, light was described as electromagnetic waves, until Einstein proposed the photoelectric effect and thus creating the concept of photon, a particle of light with momentum and energy, but no mass. It could explain why the...
For the work function, is it taken into consideration that the metal has oxidized, giving it a different energy to release the electron? Or is it so small that it is negligible?
The minimum energy required to eject an electron from the surface is called the photoelectric work function.To be precise to eject means force or throw (something) out
So energy equal to work function would surely eject an electron from metal surface
but according to the video below
At time...
What materials and equipment would be needed to for a hobbyist photoelectric effect lab kit?
If possible, trying to keep this within a budget of $50. (Cheaper if feasible).
Hello!
First of all, this is my first post here. I hope it's on the right thread.
I managed to answer most of the questions, but I think at least some of them are wrong (for example, d)). Any help would be really appreciated.
Homework Statement
A monochromatic light beam of wavelength λ=500nm...
The kinetic energy of a photoelectron is independent of the intensity of the light.
If we increase the intensity of the light, the effect is, the number of photons arriving will increase and in turn we will eject more photoelectrons. However, the maximum kinetic energy of anyone photoelectron...
Hi there,
I've been reading a textbook on Physics as applied to nuclear medicine, in particular focusing on how photons interact with matter. The textbook states (without reference) that "there are nine possible interactions between photons and matter, of which only four are of significance to...
In the photoelectric effect, we observe that the stopping potential is independent of the intensity of the light. This is readily explained by the photon hypothesis. One often sees the statement that in "the classical theory," the stopping potential should increase with intensity.
What...