Photoelectric Definition and 426 Threads

  1. S

    Photoelectric effect violating entropy?

    Hey all, I posted this a week or so ago, but never really got closure on this issue: Photovoltaic cells utilize the photoelectric effect to produce a voltage whenever an incident photon's energy is higher than the band gap of the silicon used for the cell. Consider an isolated system...
  2. C

    Photoelectric effect and kinetic energy

    hi i have a small question: how come not all emitted electrons have the same kinetic energy despite the radiation of only a single wavelength (that does cause emission of electrons) ? thanks
  3. K

    Photoelectric effect experimental data current vs. intensity vs frequency

    The photoelectric current is known to be directly proportional to the intensity of incident light with fixed frequency. Questions: 1) What are the experimental values of this proportionality constant for various fixed frequencies? 2) Is there a theoretical derivation that provides a formula...
  4. I

    Photoelectric effect compared to the particle theory

    Homework Statement in the photoelectric effect, if the frequency of the radiation is below a certain cutoff frequency, no photoelectrons are produced no matter how intense the radiation is. Why does this fact favor the particle theory over the wave theory? Homework Equations The...
  5. S

    Photoelectric effect and work function

    Homework Statement a. Which plot on the graph represents the metal with the lowest work function? b. What does the slope of the graphs represent? (graph is attached) Homework Equations threshold frequency= work function/ planks constant The Attempt at a Solution a. the lower...
  6. S

    Photoelectric effect and mercury

    Homework Statement a. Does the photoelectric effect take place if mercury is illuminated with UV light with a wavelength λ = 300 nm? The cutoff wavelength for mercury is 250 nm. Homework Equations ft= WF/h(planks constant) E=h(f) The Attempt at a Solution im not sure how to...
  7. M

    Experiment involving photoelectric effect

    Reading through the lecture notes, I had a weird idea which came in the form of an experiment that could be done. Imagine you shine light through two slits. Obviously you will get an interference pattern with bright and dark lines (constructive and destructive interference). Then on the...
  8. J

    Physical Chemistry photoelectric question stumped

    Homework Statement a student carried out a photoelectric experiment by shining visible light on a clean piece of cesium metal. She determined the kinetic energy of ejected electrons by applying a retarding voltage such that the current due to the electrons read exactly 0. The condition was...
  9. Chewy0087

    Photoelectric Effect - Electrons

    Hey there, me again =o I just want to discuss the photoelectric effect however more than that just to clear up my understanding of electrons really. I understand that electrons are 'wave packets', or a quantized wave if you like, and i'd like to know if I'm right or wrong in that? Can you...
  10. P

    Photoelectric Surface: Work Function & Kinetic Energy

    Homework Statement A certain photoelectric surface has a threshold frequency of 4.62 X 10^14 Hz. a) What is the photoelectric work function in joules? b) The surface is illuminated with light that has a frequency of 5.2 X 10^14 Hz. What is the kinetic energy of the electrons ejected from the...
  11. K

    IV curve on photoelectric effect

    Well, according to Einstein's explanation of photoelectric effect, I know that above cutoff frequency, the high frequency the incident photon is, the more electrons will be strike out. Now we add the batter on the photoelectric apparatus. At some negative voltage (stop voltage) there is no...
  12. H

    Blackbody in photoelectric effect

    any electron will be emitted if i use a black body as a metal target in photoelectric effect experimant and why??
  13. H

    Photoelectric effect and photocurrent drop

    Homework Statement Does the photocurrent drop to zero when a potential across it is equal to the kinetic energy of electrons?, because i found this not to be the case, the photocurrent reached a steady value that didnt decrease further, as i increased the potential across the anode and...
  14. H

    Finding planks constant from photoelectric effect

    Homework Statement Hello, i was doing an experiment in which you shine different colours of light onto a cathode and apply negative voltage to the anode so that the photo current reduced to a constant value. I obtained the average stopping potential for each wavelength of light (green...
  15. X

    Max Photo Current Calculation Using Platinum's Work Function

    1. Platinum has a very high work function of wo = 6.35 eV.What is the maximal photo current Io that can be achieved with an irradiation power of P = 1.27 W ? Homework Equations hf = wo The Attempt at a Solution Well, Since the only information they give here is the work function...
  16. K

    How Do You Calculate Photoelectron Emission from Sodium Surfaces?

    Homework Statement The wavelength treshold for photoelectric emission from a sodium surface is 683 nm. Calculate the energy of the electrons which are ejected when a sodium surface is illuminated by light of wavelength 500 nm. If the intensity of the light is 2.0 W/m^2 and if 1 per cent of...
  17. S

    Photoelectric Effect: Explaining Wavelength Effect on Electron Emission

    I was reading about the photoelectric effect and it described that in the classical description of light, the changing of wavelength would effect the rate at which electrons were emitted. This theory was later proved wrong when Einstein introduced the idea of photons. However this theory goes on...
  18. tony873004

    Photoelectric effect and kinetic energy

    Homework Statement Light of a wavelength 2000 Å falls on an aluminum surface. In aluminum, 4.2 eV are required to move an electron. What is the kinetic energy of (a) the fastest, and (b) the slowest emitted photoelectrons? Homework Equations K_{{\rm{max}}} = eV_0 The...
  19. B

    What Are the Photon Energies in Visible Light and FM Radio?

    Homework Statement the wavelengths of visible light range from about 380 nm to 750 nm. what is the range of photon energies (in eV) in visible light? a typical fm radio station's broadcast frequency is about 100Mhz. what is the energy of an FM photon of the frequency? Homework Equations...
  20. M

    Classical Explanation for Photoelectric Effect

    Hello. I have a question regarding photoelectric effect. My textbook says that when photoelectric effect experiment was first performed, physicists could not explain the outcome with classical physics (e.g. maximum kinetic energy depends on frequency of light, not intensity). My question is...
  21. W

    Difference between ionization energy and photoelectric effect?

    hey there, I am just school student and is a little bit confused with this quantum physics question. what is the difference between ionization energy and photoelectric emission? is the difference just that ionization energy is an electron removed from an atom in its gaseous state while that of...
  22. A

    Understanding Photoelectric Effect: Finding Binding Energy at 762nm Threshold

    How would you go about finding the binding energy of an electron to a metal surface if we are given the threshold wavelength for the initiation of the photoelectric effect as 762? Would the binding energy be the same as threshold energy?
  23. E

    Photoelectric effect cant occur with a free electron

    Homework Statement The question asks me to prove that the photoelectric effect cannot occur with a free electron. ie. one not bound to an atom. A hint is also provided: Consider the reference frame in which the total momentum of the electron and incident photon are zero. Homework...
  24. U

    Question about Photoelectric Effect versus Compton Scattering.

    In the context of interaction of photons (with energies from around visible light and upwards) and the electrons of solid matter. I've read that at the lower energy levels that the photoelectric effect is more likely to occur during such an interaction and that Compton scattering is more likely...
  25. E

    Why Does the Photoelectric Effect Eject Electrons from the Innermost Shell?

    In the photoelectric effect, the electron is emitted from the innermost shell. Why not from the outer shells? Thank you
  26. N

    Calculating max. kinetic energy (photoelectric)

    given the cutoff potential (0.25 V) and wavelength (578 nm), how do i find the maximum kinetic energy of the electrons ejected from photoelectrif surface, in both eV and J? my guess is, KE = e Vo = (1.6 x 10-19) x (0.25 V) = 4.0 x 10-20 J but if i convert that to eV, i get the same...
  27. E

    Questions on light and photoelectric effect

    1. When a certain metal reflects a certain frequency of light, it will kock loose electrons and emit them. Where exactly do these electrons come from? If a metal emits electrons, doesn't that metal eventually gain a positive charge of some sort? Is it possible for piece of metal to lise all of...
  28. S

    Photoelectric effect and current

    In a photoelectric effect experiment, which of the following changes by result in a current, if there was no current flowing previously? 1. decreasing voltage in apparatus 2. decreasing frequency of the incident light 3. making the incident light brighter 4. increasing wavelength of the...
  29. D

    Photoelectric Effect and the human eye

    Homework Statement Under favorable circumstances the human eye can detect 1.0e-18 J of electromagnetic energy. How many 600-nm photons does this represent? (Modern Physics, Arthur Beiser, 6th Edition, Pg. 89) Homework Equations My answer is unreasonably low. My mistake is probably very...
  30. U

    The Photoelectric Effect, Photon Duality, and The Double-Slit Experiment

    Hi everyone, Thanks in advance for any insights you might be able to lead me to. The photoelectric effect is a well known phenomenon where an incident photon of some energy can stimulate the emission of an electron when absorbed, so long as the energy of the photon can promote an electron...
  31. D

    How Long Until an Electron Is Emitted from Metal in the Photoelectric Effect?

    A monochromatic point source of light radiates 25 W at a wavelength of 5000 angstroms. A plate of metal is placed 100 cm from the source. Atoms in the metal have a radius of 1 angstrom. Assume that the atom can continually absorb light. The work function of the metal is 4 eV. How long is it...
  32. G

    3.)tunnel and photoelectric effects

    hello, 'QUERY3 I think we all know about tunnel effect of quantum, Also when I was studying photoelectric effect, I studied that emission of electrons for a electro-magnteic radiation of frequency less than threshold frequency is quite impossible. But then how can we say that particle having...
  33. N

    Another photoelectric effect related question

    Hi, After searching the forum I did not find an answer to my question, so here goes. In the classical theory a photon can only eject a photo electron when the energy of the photon is greater than the binding energy of the electron. This is only possible with bound electrons as some of the...
  34. S

    How Does the Photoelectric Effect Determine Planck's Constant?

    Homework Statement In an experiment to determine the value of Planck's constant a negative potential was applied to the anode of a photoelectric cell and the minimum potential required to reduce the photocurrent to zero was mesure for incident light of various frequencies. For the...
  35. S

    Finding Maximum Energy of Ejected Electrons in Photoelectric Effect

    Homework Statement For an incoming light shining on a metal surface, I am given the wavelength, the cutoff voltage, the frequency (by using f = c/w). From here, I am having trouble finding the maximun Ek of the ejected electrons in electron volts (eV) and joules (J). Homework Equations...
  36. S

    How Many Photons Does a 25W Monochromatic Light Bulb Emit Per Second?

    How many photons per second are emitted by a monochromatic light bulb (650nm) that emits 25 W of power? W=hfo hf=Ek + W P=W/t is there a way we can find power? how do I solve this question?
  37. A

    Photoelectric Emission: Why Does Number of Electrons Decrease?

    Hello This is a question regarding photoelectric emission. When frequency of the radiation increases at a constant intensity, the number of electrons emitted per unit time decreases. Why is that so? p.s. I need an answer ample for Alevel purposes. Not too complex that is.
  38. M

    Photons and the photoelectric effect

    Homework Statement the maximum wavelegnth for which an electromagnetic wave can eject electrons from a platinum surface is 196 nm. when radiation with a wavelength 141 nm shines on the surface, what is the max speed of the ejected electrons? Homework Equations f=c/λ E=hf E=Φ+K...
  39. H

    A question about Photoelectric Effect

    [SOLVED] A question about Photoelectric Effect According to my teacher "photoelectric current is independent of frequency but dependent on intensity". This statement seems to conflict the following exercise: "In an experiment to investigate the photoelectric effect, monochromatic light is...
  40. H

    Does the Photoelectric Effect Indicate Quantized Energy Emission by Atoms?

    Homework Statement Do photoelectric effect suggest that the emission of energy by an atom be quantized Homework Equations The Attempt at a Solution I think it is true as photoelectric effect told us that atom emitt energy in terms of electron.
  41. I

    What are the angles of photoelectron emissions from a metal surface?

    hey.. can some one tell me... when photo electrons come out of the metal surface... then are those emissions normal to the surface or they come out at any angle from the surface.
  42. D

    Photoelectric effect (questions)

    hi, Just had a few questions on the topic. With say a sheet of metal exposed to sun light, what happens when all the electrons are gone? Is it still a sheet of metal? Just without the negative charge? will it look any different? And how long until all electrons are gone? Is there a life...
  43. A

    Undergraduate Lab: Photoelectric Effect Experiment

    hi, i was wondering if there were any websites or any links that talked about performing the photoelectric effect for an undergraduate lab? i have to come up with a proposal for an experiment and i was considering the photoelectric effect but didnt really know what would be needed in terms of...
  44. P

    Understanding the Photoelectric Effect: Electrons and Energy

    Is in the photoelectric effect, the electrons are oppositing the electromagnetic field or they are excited from the energy?
  45. T

    Electron Configuration After Photoelectric Effect

    I'm not very well versed in the photoelectric effect, but as it happens, I found a brief description of it in my chem book. I'm really curious to know what really occurs to an atom's configuration right after its exposed to light. Let's say a photon hits a Zinc atom at threshold level and its...
  46. rohanprabhu

    Does intensity determine the occurrence of the photoelectric effect?

    For the photoelectric effec to take place for a certain metal, there is a minimum frequency that the incident radiation must have, also called the threshold frequency. Let us call it f_o. The electron is emmitted only when a minimum amount of energy is provided to it so that it can repulse...
  47. J

    The Photoelectric Effect question

    My physics class is currently studying the photoelectric effect, and I was wondering if anyone could clarify this for me: "Only photons of a high-enough frequency, (above a certain threshold value) could knock an electron free. For example, photons of blue light had sufficient energy to free...
  48. G

    Albert and the Photoelectric Effect

    Homework Statement My question isn't about a specific problem, but I was wondering if anyone had a good website that explicitly explains Einstein's experiment for the Photoelectric Effect. I've had trouble finding what he did. The only procedures that I've come across are those of proving he...
  49. N

    Can the Photoelectric Effect Distinguish Between Classical and Quantum Theories?

    Homework Statement In the photoelectric experiments the photocurrent is proportional to the intensity of the light.Can this result alone be used to distinguish between the classical and quantum theories? Homework Equations The Attempt at a Solution As I know, this feature of...
  50. H

    Photoelectric Effect: Is There a Problem?

    My physics teacher told me that in photoelectric effect, only one photon can be absorbed by one electron. Not more than one photon can be absorbed during the emission of electron. But a beam of light is a stream of photons! The chance for two or more photons colliding with the same electron...
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