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

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2answers
144 views

Super massive Black Hole and photon reduction [closed]

This is a picture of 2 galaxies taken from The Hubble. The arrow shows a smaller galaxy's black hole starving of the usual stars because of the binary rotation about the bigger galaxy that is pulling ...
3
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2answers
44 views

What is basic difference between photoelectric effect and Compton effect?

What is basic difference between photoelectric effect and Compton effect? In both case a photon hits a loosely bound electron So whats the difference? We get current in photoelectric effect but not in ...
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0answers
28 views

How to increase the frequency of light

If we want to increase the energy of the emitted photoelectrons (in P.E) then we should increase the energy of the photons which are related to the frequency of the light, so how is the frequency of ...
6
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1answer
587 views

How is a CCD able to collect images in drastically different lighting conditions?

I have read the basics of how a digital camera works. As much as I have understood, the digital cameras have a device called a CCD on which photons coming from the lens are incident. The CCD then ...
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2answers
67 views

Is photoelectric effect really true?

All books say only a single photon can remove an electron at a time. But we see that during thermal emissions electrons are removed by heat waves which are actually infrared rays. These infrared rays ...
3
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1answer
33 views

Has time lag been calculated?

Books says time lag in which an electron leave atom, in photoelectric effect, is negligible. Is this negligible value been calculated?
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16 views

How to measure the maximum kinetic energy of electrons emitted due to photoelectric effect?

From Einstein's photoelectric equation, $$hf = \phi + k.e_{\text{max}}$$ where $\phi$ is the work function of the metal. My question is : how to experimentally determine the kinetic energy of ...
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0answers
34 views

Why is there a longer time lag if light behaves as a wave?

In this problem: According to a model based on the electromagnetic theory of light, the electron absorbs all the energy that is incident on the surface within a distance of $5.0\times 10^{-11}\ ...
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1answer
44 views

So why are photoelectric panels flat? (Part II)

In this post So why are photoelectric panels flat?, I've asked if we could use flat photoelectric panels with hemispheric cells. Most of the answers seemed to say it would not work. Anyway, I'm ...
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4answers
1k views

So why are photoelectric panels flat?

In this post Why not use our own light production to produce new energy instead of wasting it?, I naively asked if it was possible to also recycle our own lightning at night. someone, in his answer, ...
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2answers
63 views

Why doesn't silicon emit light? [closed]

Why doesn't silicon re-emit light when light falls on it? Or if it emits light then why we can't see it?Hence it has valence electrons.
2
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0answers
46 views

Why not 2, 3, 4, or more photons can be absorbed by single electron? [duplicate]

During Photoelectric effect and other such phenomenon, when light is made to fall on metal surface, single photon is absorbed by the single electron present in metal atom. Why not 2, 3, 4, or more ...
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0answers
25 views

Extraction efficiency in photoeffect

I am looking at the extraction efficiency of the photoeffect (how many electrons end up in vacuum per photon). I have read in this forum that 1e-5 or less electrons make it outside of metal. Reason is ...
3
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2answers
49 views

Does laser light with less than the work function still ionise some atoms?

If a gas is illuminated with a laser of a frequency less than (but more than half of) the work function of the atoms in the gas, the atoms will be excited into Rydberg atoms. Is there a finite chance ...
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2answers
63 views

Photoelectric effect

Why the photoelectric effect is observed only for metals and not for non-metals? Isn't it possible for the photon to release an electron from a non-metal surface?
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1answer
45 views

Kinetic energy of an electron with de Broglie wavelength $\lambda$

If an electron has de Broglie wavelength $\lambda$, can I write it's kinetic energy $E = \frac{hc}{\lambda}$? If not then what energy does the equation represent and when can the equation be used ?
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3answers
36 views

Photoelectric Effect Changing The Charge of a Metal?

So the photoelectric effect causes metals to emit electrons in contact with light. I have two questions... 1) Does this keep happening until no more electrons are being emitted? 2) Can't this effect ...
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1answer
51 views

Why doesn't photoelectric current increase with frequency of the incident wave?

If the frequency of the incident wave is increased, then the kinetic energy of the photoelectrons increases. If so, why doesn't the photoelectric current increase? If the kinetic energy of electrons ...
2
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0answers
21 views

Compton effect in photo-electric?

In photo-electric effect Einstein said that photons incidents on material and gives their energy which will gives kinetic energy to electrons. But i also want to know that why Compton's effect not ...
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1answer
36 views

Is there a relationship between kinetic energy of emitted electron and photoelectric current?

I know that photoelectric current is dependent upon intensity of incident light. But it should also be dependent upon kinetic energy of emitted electron because mathematically $I=Q/T$. So if kinetic ...
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0answers
32 views

Why doesn't saturation photocurrent depend on frequency of incident ray, keeping intensity constant?

We know that intensity I = nhf, where n is no. of photons striking metal surface per second per unit sq unit area, and f is frequency of incident ray. In the book it was said that if we change the ...
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1answer
94 views

If photons have mass then how can they travel at speed of light? [closed]

Anything that has mass must be slower than speed of light. If they are travelling at speed of light they must contain infinite energy which should be able to destroy everything, clearly thats not ...
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3answers
97 views

Does a single photon's energy depend on frequency? (photoelectric effect)

Essentially this question boils down to "why does the energy of light depend on frequency?". The analogy my textbook (pg. 272 principles of chemistry A molecular Approach 3rd edition by Nivaldo J. ...
2
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2answers
103 views

Can one photon emit two electrons?

My question refers to the photoelectric effect. I have heard that it is possible, that for one photon, two electrons leave the irradiated metal. Is this correct and by which process can this be ...
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0answers
32 views

Why does stopping potential depend on intensity? [closed]

Yes, the stopping potential shouldn't depend on the intensity of the incident photons theoretically, but an experiment using a PASCO h/e apparatus shows that when we use a Variable Transmission Filter ...
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0answers
29 views

Does nature of light depends on its Time of Interaction?

I was trying to understand how to "feel" about light. I have formed a notion which I couldn't find anywhere. So please tell if I am correct. Also please give theoretical explanations if possible (and ...
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2answers
67 views

Photoelectric effect and energy of light

I have a doubt about photoelectric effect and the nature of light in general. From what I understood, in order to ionize a piece of some material, I need an electromagnetic wave with a frequence ...
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1answer
112 views

Relationship Between Stopping Voltage and Photocurrent

Online, I found a graph of photocurrent vs. stopping voltage: And I can’t figure out how photocurrent and stopping voltage have such a relationship. Stopping voltage is proportional to maximum KE ...
2
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1answer
64 views

Einstein's 1905 “Concerning an Heuristic…emission and transformation of light”

I'm currently attempting to read Einstein's annus mirabilis papers, starting with his introduction of the quantization of light in the paper: "Concerning an Heuristic Points of View Toward the ...
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1answer
46 views

Effect of frequency on magnitude of photo current

In a photoelectric experiment, if the frequency of incident light is slightly raised while holding intensity constant, I understand that the number of incident photons decreases. This in turn results ...
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2answers
304 views

Why does wavelength determine the energy of a photon?

The professor for my first-year university chemistry class remarked that the wavelength of a photon determines its energy. Why is it that the case? I've only completed high-school physics so far, so ...
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1answer
49 views

Why does current vary continuously with potential in the photoelectric effect?

In the photoelectric effect, for a given intensity and frequency of light source, why does the current increase as you decrease the retarding potential, below the stopping potential. Isn't the ...
3
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2answers
213 views

Can I use fluorescent light bulbs to calculate Planck's constant?

We did an experiment today to calculate Planck's constant, $h$. We measured the knee voltages $V$ of different LEDs (red, green, orange, blue, violet) and plotted them against the frequencies $f$ of ...
0
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1answer
47 views

Dependence of saturation current in photoelectric tube on the time taken by the electron to reach the opposite plate?

The kinetic energy of an electron in a photoelectric tube increases with increase in the applied voltage across the plates of the tube, thus the velocity of the electrons also increases. Accordingly ...
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1answer
122 views

Can electron jumps to higher energy state without absorbing photon?

The shorter the wavelength of the electromagnetic wave the more energy it carries, when it hits an atom and gets absorbed the electron gains kinetic energy and jumps to higher energy state. Are there ...
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2answers
139 views

Why is the K shell electron preferred in the photo electric effect?

I have read in many books and on Internet as well that photoelectric effect is only possible when an electron is emitted from the K shell of the metal. Why not other bonded electrons?
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2answers
184 views

Light and momentum question? [duplicate]

Each photon of light bulb carries momentum. Why does the light bulb not recoil from conservation of momentum?
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1answer
834 views

What's the difference between the work function and ionisation energy?

In a particular textbook, the work function of a metal (in the context of the photoelectric effect) is defined as: the minimum amount of energy necessary to remove a free electron from the surface ...
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1answer
42 views

Dissolving photoconductor (TiOPc) from Laser Printer drum possible?

When I was thinking of a Lab-On-a Chip Application which combines a lensless microscope and an optical tweezers I saw the ...
1
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1answer
116 views

Is the photon's wave function the same as an electromagnetic wave(light)? [duplicate]

The first that i have been taught in Quantum Mechanics is the photoelectric phenomenon. Without analyzing it, it concludes that when we shine light at the circuit(roughly speaking), the work required ...
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2answers
53 views

Would an ordinary or fluorescent lightbulb generate electricity when exposed to light?

I was wondering whether the physic laws or the nature in which lightbulbs are constructed would allow for lightbulb to generate electricity when subjected to strong (intensive and concentrated) ...
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1answer
45 views

Why don't electrons dislodge with higher intensity?

I understand that photo-electrons are not produced with increased intensity because frequency is what matters, however could someone give me a good intuition of why this is the case? What exactly do ...
0
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1answer
31 views

How to calculate the potential of a photocell?

My guess is that because the wire is connected to a single point on the plate, we can treat it as a point charge and use the formula: $$V = k\frac{k(\pm q)}{|r|}$$ But I think there are different ...
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0answers
15 views

How does the maximum kinetic energy of an ejected electron affect what happen to it after being ejected? [duplicate]

So I just learned: $$K_{max} = hf - \phi$$($\phi$ for ionization energy) I wonder what will happen if $K_max$ is zero. Will it be attracted back to the ionized atom it has come from since it doesn't ...
1
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1answer
34 views

Will ionization energy be affected by screening effect?

It would be logical to think that the more electrons are ejected from an atom, the harder it is to eject more. I just learned about photoelectric effect experiment. The book is kinda telling me the ...
1
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1answer
154 views

Quantum efficiency of Photoelectric effect

What is the typically measured quantum efficiency of photoelectric effect experiments involving ultra violet photons incident upon common metals like copper or aluminum. In case I'm not being clear, ...
0
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1answer
215 views

What if I double the frequency of incident light in photoelectric effect?

The photoelectric effect occurs when the frequency of incident radiation is above a threshold frequency. If we double this incident frequency, what effect will it have on the experiment? Also what ...
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1answer
123 views

Photoelectric Effect - Dependence of current on frequency

We all know that the amount of current flowing b/w the plates is independent of the frequency. If I were to ask why doesn't it depend then you'd probably say that it depends on the number of electrons ...
1
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2answers
123 views

How long does it take for an excited electron to return to ground state?

During a mock Cambridge interview, one of the questions was about how small a computer could theoretically be.The way I approached it was in terms of what something must be to be considered a ...
0
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1answer
67 views

Why isn't this calculation of the energy of a light wave correct? [closed]

I'm trying to calculate the energy $J(T)$ that monochromatic light wave with electric field strength $E(T)$ supplies to unit electric charge over period of time $T$: $J(T)=\int\limits ...