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

learn more… | top users | synonyms

1
vote
1answer
166 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 ($\phi = 1.95 \, \mathrm{eV}$). ...
0
votes
1answer
108 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 ...
1
vote
2answers
57 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 ...
2
votes
2answers
349 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 ...
3
votes
2answers
318 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 ...
9
votes
1answer
246 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 ...
0
votes
1answer
117 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?
5
votes
3answers
195 views

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 ...
1
vote
1answer
40 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 ...
1
vote
1answer
166 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. ...
2
votes
3answers
2k 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 ...
1
vote
2answers
112 views

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 ...
6
votes
2answers
1k 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 ...
0
votes
1answer
241 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 ...
0
votes
0answers
130 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 ...
0
votes
2answers
45 views

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 ...
2
votes
1answer
150 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 ...
2
votes
1answer
252 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, ...
2
votes
2answers
10k 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 ...
0
votes
1answer
267 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 ...
6
votes
2answers
2k 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)?
5
votes
2answers
2k views

Is plant photosynthesis more efficient than solar panels?

Is photosynthesis more efficient than solar panels? If so, by how much?
1
vote
1answer
191 views

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.
4
votes
1answer
114 views

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 ...
1
vote
1answer
118 views

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. ...
0
votes
1answer
30 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 $8*10^{17}$ ...
1
vote
1answer
223 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 ...
1
vote
0answers
661 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 ...
0
votes
2answers
530 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 ...
1
vote
1answer
99 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 ...
1
vote
2answers
73 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 ...
0
votes
3answers
626 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 ...
2
votes
2answers
2k views

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 ...
0
votes
1answer
220 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 ...
0
votes
1answer
139 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 ...
0
votes
1answer
477 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 ...
0
votes
1answer
163 views

Light behaves as a particle or wave in this thought experiment?

Consider a metal plate, on which a light of appropriate wavelength is incident such that it creates an interference pattern. The wavelength is chosen such that it can cause detectable photo-electric ...
1
vote
1answer
239 views

Doubt in solving question related to photoelectric effect?

Question:- When a beam of $1.06eV$ photon of intensity = $2.0 W/m^2$, falls on a platinum surface of area $1.0*10^{-4}m^2$, and work function $5.6eV$, $0.53$% of incident photons ejected photo ...
1
vote
0answers
793 views

Intensity of light that produces largest current in Photoelectric Effect + Stopping Voltage Question

For the first image: For the Sodium metal, the Current produced by the cell is the highest when shined on by 196nm light - Not the highest, why is that? What determines the intensity of the light ...
2
votes
4answers
12k views

In famous Einsteins Photoelectric effect, Why does intensity of light doesn't raise the kinetic energy of the emitting electrons?

The work function of any metal is no doubt constant for it is related to electromagnetic attraction between electrons and protons. However on increasing the intensity of any light source the kinetic ...
0
votes
1answer
128 views

Photoelectric effect - shining light on a silver ball

Lets say we have a silver ball hanging on an isolator string. The work function $A_0$ of a silver and radius $r$ of the ball are known. Now we shine light of known $\lambda$ on it from all the ...
0
votes
1answer
927 views

Photoelectric effect - calculating a current in the photocell in which only $5\%$ of photons manage to cause the effect

I have been trying to solve a problem about photocell and have obtained the wrong result. Can anyone tell me where did I go wrong? So it is easier I will write down all my calculations. We have a ...
0
votes
3answers
227 views

Photoelectric effect: according to classical physics?

This is a sample test question I've encountered twice in some practice chemistry finals. I'm a little bit confused about what it's asking. You are conducting an experiment on the photoelectric ...
0
votes
1answer
128 views

Do photoelectrons move fast enough to use special relativity? (+ homework)

What are the speeds of the photoelectrons which are knocked out of the metal during photoeffect? Do i have to use special relativity? I am having trouble solving a homework using relativity. But if ...
0
votes
0answers
40 views

Experimental study of the Photoelectric effect [duplicate]

As I was reading about the experimental arrangement for photoelectric effect, I saw a diagram that puzzled my knowledge of electrodes. I found that in the experimental setup the cathode of the ...
26
votes
6answers
4k views

Can the photoelectric effect be explained without photons?

Lamb 1969 states, A misconception which most physicists acquire in their formative years is that the photoelectric effect requires the quantization of the electromagnetic field for its ...
4
votes
1answer
101 views

Why are there multiple L-edges in X-ray photoionization?

In heavier elements, why are there multiple L-edges in photoionization? In the image below, what do $\rm{L_{I}}$, $\rm{L_{II}}$ and $\rm{L_{III}}$ stand for? In this handout, (page 141 Figure 7.13), ...
1
vote
1answer
69 views

Contact electricity and photoelectric effect

Most universities provide an experiment about the photoelectric effect to determine $h$ by measuring the stop voltage against the light frequency and calculating the slope $h/e$. But mostly they also ...
1
vote
1answer
4k views

Finding the maximum kinetic energy of any photoelectrons?

An incident photon, $f=5.5\times 10^{14}\ Hz$, hits a metal with a work function of $2.8\ eV$. Find the maximum kinetic energy of any photo-electrons (in Joules). I'm confused exactly how to do ...
2
votes
1answer
231 views

Color of a Metal's Threshold Wavelength?

How do I find the color of the threshold wavelength if the metal has a threshold wavelength of $\mathrm{6.5\times 10^{-7}m}$? I know that converts down to $\mathrm{650\ nm}$, but can I still use the ...