The observed behavior in which light falling on certain metals can eject electrons from the surface.
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0answers
30 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 ...
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1answer
24 views
Charge gained due to photoelectric effect [closed]
Here I think, one beam will knock out just one electron. So, I am not able to even understand what the question says. Please someone give a hint as to what the question asks...
As source of the ...
0
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1answer
52 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 ...
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1answer
34 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 ...
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1answer
27 views
Color of an incident photon?
If the incident light at 360nm causes photoemission of electrons, wouldn't the color be ultraviolet? I know that really isn't a color, but that's what my chart of the light spectrum says.
Unless I ...
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1answer
35 views
Confused about the Photoelectric Effect?
If an incident photon with frequency f hits a metal with a work force of w:
How do I find the color of the incident photon and the threshold frequency of the metal?
I missed out on the days in my ...
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1answer
79 views
Time to emit electrons
Explaining the photoelectric effect, our teacher told us that back in that time, they calculated the time that an electron would take to be emitted from an atom if the energy got to the atom in a ...
1
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1answer
104 views
Specific electron energy gap values $E_{i+1}-E_i$ vs. photons with arbitrary energy $\hbar \omega$
The energy levels of electrons in an atom are quantized $E_i$. A photon of a specific momentum $\vec p$ and energy $$\omega=(E_{i+1}-E_i)/\hbar$$ hits an atom and gets absorbed. Okay now say the ...
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2answers
192 views
What are thermal energy distributions?
I am trying to understand the photoelectric-effect deeply. My teacher used the Planck's law and integrated it to deduce the Stefan-Boltzmann law. He somehow showed some quantum-physical ...
3
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1answer
134 views
Classical (or semi-classical) interpretation of photoelectric effect?
This site says that "it has recently been proven that the photoelectric effect can be interpreted classically (or at least semi-classically) in non-particle, wavelike terms". Is anyone familiar with ...
2
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1answer
68 views
Ejected Electrons with 0 KE?
So I was taught that:
Kinetic Energy (of electron) = Energy (of photon) - Ionization Energy
If E(photon) = IE, then KE=0 of the electron.
What does this physically/theoretically mean?
My current ...
1
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1answer
66 views
How does the specific frequency of EM Radiation relate to displacing electrons from their orbits?
I've only a general grasp on how all this works, so it could be I'm asking this poorly or misunderstanding what happens. With that said:
The energy of EM radiation is a function of its frequency. ...
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1answer
57 views
Assuming collision , are there fundamental forces associated with absorbtion?
I just learned that strong and weak nuclear forces relate to decay/emission.
I know absorbtion depends on Energy levels(QM) and heat(thermodynamics , kinetic energy , entropy) and E = gamma mc^2 ( ...
2
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1answer
424 views
Meaning of the first and second laws of the photoelectric effect
I was reading the introduction to quantum mechanics in my physics book and it begins with a discussion of the photoelectric effect and energy quantas.
The first law, the one that says that the ...
0
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1answer
165 views
Expression for the (relativistic) mass of the photon [closed]
I started learning a bit ahead from an old physics book, and they were discussing the photoelectric effect and after that Planck's hypotheses and energy quantas.
The book said that the mass of a ...
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5answers
144 views
Photoelectric effect without light rays
For electromagnetic waves we have the photon association, one imagines light as particles "flying around".
What is the analogy for a constant electrical field, one which doesn't change in time ...
0
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0answers
100 views
Cross section of photoelectric absorption vs Thomson scattering cross section
I am interested in more less the same issue as asked here but my question is:
Why for the low X-rays the photoelectric absorption is dominant over Thomson/Compton scattering? I am considering the ...
3
votes
3answers
1k views
Compton scattering vs. photoelectric effect
Say a photon hits some atom.
What determines whether there will be a photoelectric effect (photon is absorbed, electron is released) or whether there will be a Compton scattering (the photon is ...
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2answers
320 views
Schematic design of the apparatus (photoelectric effect)
I think I understand the basic idea of photoelectric effect but there are two things in the schematic diagram of the apparatus for the investigation of the photoelectric effect which I do not ...
2
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1answer
117 views
Why don't metals disintergrate in light?
I've been learning about photoelectricity. An electron can gain the energy from a single photon, and if that energy is greater than the work function of the metal the electron can leave the metal. ...
1
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0answers
93 views
An electron is subjected to an electromagnetic field using the canonical equations solve
So I was given the following vector field:
$\vec{A}(t)=\{A_{0x}cos(\omega t + \phi_x), A_{0y}cos(\omega t + \phi_y), A_{0z}cos(\omega t + \phi_z)\}$
Where the amplitudes $A_{0i}$ and phase shifts ...
4
votes
1answer
221 views
Photoelectric effect: Experimental Physics
Suppose you are doing an experiment to determine the work function of a metal.
You get $KE_1$, $\nu_1$ and $KE_2$, $\nu_2$.
We know that $KE = h\nu - W$ but when you solve the simultaneous ...
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2answers
2k views
What happens to the absorbed light energy?
When light comes across with a solid material, some of it is reflected, some of it passes through and some of it is absorbed. I understand the reflection and passing through, but I don't understand ...
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2answers
325 views
Is energy exchange quantized?
In the photoelectric effect there is a threshold frequency that must be exceeded, to observe any electron emission, I have two questions about this.
I) Lower than threshold:
What happen with lesser ...
3
votes
3answers
379 views
How bright can we make a sun jar?
A sun jar is an object that stores solar energy in a battery and then releases it during dark hours through a led.
Assume:
a $65cm^2$ solar panel
a 12h/12h light/dark cycle
insolation of ...
7
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1answer
885 views
Does Tesla's photoelectric “solar cell” really work?
Tesla patented a device for gathering energy from light, using the photoelectric effect. (US 685,957 - Apparatus for the Utilization of Radiant Energy):
Basically just a sheet of "highly polished ...
2
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1answer
113 views
In photo-electric experiment, if the light is exposed to a metal plate for a long enough interval, does the plate become lighter?
I know from the book that electrons will be kicked out from the metal plate if the light of appropriate wavelength is exposed to the metal plate.
My mental model says if we let the light expose the ...
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3answers
2k views
photoelectric effect
A 1.0 mW laser ($\lambda$ = 590 nm) shines on a cesium photocathode (ϕ = 1.95 eV). Assume an efficiency of $10^{-5}$ for producing photoelectrons (that is, 1 photoelectron is produced for every 10^5 ...
4
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2answers
4k views
How would I calculate the work function of a metal?
In the photoelectric effect, the work function is the minimum amount of energy (per photon) needed to eject an electron from the surface of a metal. Is it possible to calculate this energy from the ...
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3answers
363 views
Why did people expect the number of electrons emitted because of the photoelectric effect to rise with the radiation's intensity?
The number of electrons emitted because of the photoelectric effect
rises with the frequency of the radiation
is not influenced by the intensity of the radiation (As Chad points out, this is wrong, ...
