The observed behavior in which light falling on certain metals can eject electrons from the surface.

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saturation current in photoelectric effect

While studying photoelectric in my school, my teacher drew a graph of current versus the potential difference across the two electrodes. I am not able to understand why do we get saturation current. I ...
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32 views

Photoelectric effect intensity

I understand the PE effect quite well but I'm failing to understand one thing. Intensity is the amount of energy per second incident to a given area. So can you can increase the intensity by either ...
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1answer
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Photoelectric effect experiment: is charging time proportional to current?

I'm not really sure what tags to add to this question, but definitely this is just an introductory physics experiment. Let me refresh you first with the basics of the photoelectric effect. We all ...
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How can Einstein explain particles of light without particles?

how can Einstein explain particles of light without particles? For his Nobel prize he used Newtons explanation except both he and Newton agreed that aether solved the problem of going through holes. ...
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46 views

Why do electrons eject only if the frequency of incident ray is greater than the threshold frequency? [closed]

Why do the electrons start moving even if the dim light (less intense) of a specific frequency falls on the material ?
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1answer
29 views

Photoelectric Effect and Electromagnetism Voltage Problem

Whenever a book talks about the photoelectric effect, it talks about how we can use a battery to attain a $V_{stop}$. Basically, you are making the metal plate on which you don't shine light have a ...
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39 views

Photoelectric effect stopping potential

$q_eV_s = hf - \phi$ My question is... suppose we are testing the photoelectric effect. One plate is illuminated. We have applied the stopping potential. Suppose an electron leaves one plate with $KE ...
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Photoelectric effect Experiment - What's the voltage bias of the set up?

What's the bias of the setup? Forward / Reverse? I'm doing a photoelectric effect experiment.The experimental setup involves a photocell, which has an emitter (cathode) Potassium and a ...
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222 views

Is Photoelectric Effect continuous or discrete?

I don't understand how electrons and photon interact with each other when a metal surface is illuminated with light. I've read that below a certain threshold frequency or wavelength of light, no ...
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68 views

Does quantum mechanics contradict macroscopic determinism?

I am wondering whether it is true to ask whether determinism is still completely viable at macroscopic scales given that the constituent particles behave according to QM when the dimensions get small ...
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53 views

why stopping potential in the photoelectric effect is negative?

I am reading an introduction article for photoelectric effect. It is said that the variable potential was tuned until no single one photoelectron can reach the electron collection plate. But if we ...
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What is the difference between photoelectric effect and Compton scattering?

What is the difference between photoelectric effect and Compton scattering? These two effects explains interaction of photon with electron. Why in photoelectric effect whole energy of photon is used ...
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Does the photoelectric effect require a battery or a circuit?

This is how the professor showed us the photoelectric effect: Does the photoelectric effect require: a. a battery? what happens if the battery is replaced with a wire? b. a circuit? what happens ...
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42 views

Energy loss in the photoelectric effect

If a photon hits an electron with an energy that is less than the energy required to change the energy level of an electron, what happens to the energy of the photon (is it not absorbed and just pass ...
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1answer
80 views

How to calculate the photoelectric effect with photon efficiency?

I am not sure exactly where to go with this problem. The problem states: "A $1.3 \, \mathrm{mW}$ laser ($\lambda = 545 \, \mathrm{nm}$) shines on a cesium photocathode ($\phi = 1.95 \, \mathrm{eV}$). ...
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1answer
73 views

Is the photoelectric effect a type of nuclear decay?

If the frequency of light is $f$ and if $f \ge f_t$, where $f_t$ is the threshold frequency, electrons are emitted if light is shined on a metal surface. By my understanding, the light comes in and is ...
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2answers
50 views

Why photon has a wave nature? [duplicate]

Wave theory does not account for the photon model, which was developed only to explain quantum effects like photoelectric effect. Then why do we talk about a photon's reflection and rarefaction, as ...
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3answers
99 views

What happens to a metal plate in the photoelectric effect?

In the photoelectric effect the electrons are supposed to be removed from the plate if light of appropriate wavelength hits the plate. If electrons are removed, the plate should get ionized ...
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1answer
107 views

Is there a way to calculate the photoelectric effect in QED via a Feynman diagram?

The photoelectric effect is the historic origin of the quantum particle description of light. From it we learn that when light is shone onto a metal single photons interact with single electrons in ...
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188 views

How is the Photoelectric Effect affected by Blue-Shifting

I was thinking about the Photoelectric Effect and Blue-Shifting when I came up with a thought experiment that I couldn't think of an answer for. The thought experiment is as follows: A metal plate is ...
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77 views

Photoelectric Effect - How are the electrons regained?

When the photons with enough energy impinge on a photocathode, it emits electrons. Does this mean that the solid will lose all its electron at one point? If not, how are electrons restored?
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What if all the electrons leave a metal?

I was studying photoelectric effect. Then I thought that what will happen if all the electrons from a metal piece come out as photoelectrons by using a light source of particular frequency? Will the ...
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1answer
30 views

Is photoelectric emission same as ionization or are they different?

According to my book the mechanism of ionization is: "If an atom absorbs enough energy so that an electron is raised to the highest energy level the electron becomes free of the atom i.e. ionization ...
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1answer
79 views

Is a vacuum needed in photoelectric effect?

This question was asked to me. My first thought was that electrons may ionise the air and potential difference that was applied may increase or decrease the current which should have been observed. ...
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362 views

What is the relation between photoelectric current and frequency of incident light?

I googled it a bit and found that photoelectric current is independent of frequency(of incident light).Some further look revealed that actually "saturation current" is independent of frequency.I could ...
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photo electric effect question

When EM radiation with fixed intensity and frequency strikes the metal plate, are the outgoing electrons at higher energy if the plate were charged to some potential than if the plate were simply ...
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894 views

Does the photoelectric effect obey Ohm's law?

So, I've been reading about the photoelectric effect for my modern physics class, and I was confused about how Ohm's law works in relation to it. Say we have a photoelectric apparatus that simply ...
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125 views

Electromagnetic radiation and black body radiation

I was taught today that the Electromagnetic wave Theory is unable to explain black body radiation. The example that was given to me: When a metal is heated, it emits different frequencies of light as ...
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63 views

Changing threshold frequency

Consider a metal surface which is being continuously irradiated with a light with frequency greater than the threshold frequency. After some time, all the electrons should have been emitted from the ...
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Atomic physics - photoelectric emission

I understand that when photoelectric emission occurs: $$h\nu = h\nu_o + K.E.$$ Where $\nu_o$ represents the threshold frequency. What I don't understand is what happens if the frequency is just equal ...
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80 views

Direction of Photo Electron Emission

I was looking for information on how the photo electrons are emitted when under X-ray radiation. In this ancient review paper here http://authors.library.caltech.edu/1551/1/WATpr28.pdf they state that ...
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88 views

What happens when work function = hf

What happens when the photon which hits a metal surface has energy equal to the work function of that surface? $$\phi = hf$$ I realise the emitted electron will have no kinetic energy after escape, ...
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2answers
2k views

Stopping potential in the photoelectric effect, collector work function

In this question I am talking about the following situation: Now, I know that the max kinetic energy of the electrons emitted is $KE_{max} = h\nu - e\phi_{em}$ where $\phi_{em}$ is the work ...
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1answer
95 views

Photoelectric Effect Problem

Say in a photoelectric experiment, we find a stopping potential of 1.85V for $\lambda=3000\overset{\circ}{A}$ and of 0.82V for $\lambda = 4000 \overset{\circ}{A}$. How can I get the Planck's ...
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723 views

Why do electrons in an atom 'fall' back to the ground state?

Why, after absorbing a photon does an atom's electron 'fall' back to its ground state (what causes it to immediately lose its absorbed energy)?
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Is plant photosynthesis more efficient than solar panels?

Is photosynthesis more efficient than solar panels? If so, by how much?
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CCD's and the photoelectric effect

Do charge coupled devices as found in telescopes use the photoelectric effect if not what eles librates the electons. Also what is charge intergration in reation to CCD's.
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Photomagnetic effect

I just saw an article on wikipedia: http://en.wikipedia.org/wiki/Photomagnetic_effect "This article appears to contain unverifiable speculation and unjustified claims. Information must be verifiable ...
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1answer
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What causes the Fermi Tail in Photoelectric effect?

I did a Photoelectric effect experiment, with this setup (schematic): Figure 1 Scheme of the setup The kathode is made of Potassium. Light is passing through the monochromator and on the kathode. ...
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1answer
29 views

Do I need to take both particles' momentum into account in photoelectric emission? [closed]

An aluminum dust particle of mass $m=2.2*10^{-18}$ grams is floating in space ( initial velocity is zero). The particle emits electron under influence of a photon whose frequency is $8*10^{17}$ ...
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133 views

The probability of electron-hole pair recombination as a function of physical proximity

When we shine line of an appropriate wavelength at a metal, e.g. gold, such that there is sufficient energy to promote an electron from the valence band to the conduction band, we'll generate with ...
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383 views

How does a Photocell/Photoresistor work? [closed]

I'm just curious highschooler beginning an interest in electronics and this concept of light detecting resistance component is really intriguing to me. I assume it's an application of the ...
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205 views

Photoelectric effect: current vs wavelength

In an experiment where the type of metal,intensity of light and potential difference across a battery is kept constant at 2V the results show that an increase in wavelength, obviously in turn ...
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1answer
85 views

Unusual observation in photoelectric effect simulation

I was studying a photoelectric simulation (http://phet.colorado.edu/en/simulation/photoelectric) and I observed a really unusual thing. When I held intensity and potential at a constant value and then ...
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71 views

Why 'max' in $hf=\phi+{1\over{2}}mv_\text{max}^2$?

The equation for the photoelectric effect is $$hf=\phi+{1\over{2}}mv_{\text{max}}^2$$ How does this make sense given that $hf$ describes a single photon and ${1\over{2}}mv_{\text{max}}^2$ describes ...
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274 views

where does the photon go after scattering?

My question is about photo electric but it could be applied to other daily routine phenomenon. As we know rest mass of photon is zero. When a photon strikes the ...
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2answers
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Relationship between stopping potential and work function

Suppose I have a cathode with a work function of 3eV and an anode at a potential of 2V above the cathode. If a photon having 2eV of energy hits the cathode, what happens? A. An electron is emitted ...
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129 views

Photoelectric Effect, Why can't two quanta interact with an electron at the same time?

I understand that assuming light is quantized implies that if a lower energy interacts with metal, it is possible that that quanta will not have enough energy to eject the electron. What prevents two ...
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115 views

Why photon-electron energy transfer can't occur in steps or does it?

The process of exchange of energy between a photon and an electron only occur after a specific energy called work-function of the material. Thus, the energy transferred is quantised due to the fact ...
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403 views

Can a photon survive a collision? If so, is it at rest during the process?

Background Irving Kaplan, in Article 6.7: The Compton Effect of Nuclear Physics (2nd Ed.) explains the Compton effect as follows: Compton (1923) was able to show that when a beam of ...