Photoelectric Definition and 443 Threads

Hi I would like to know if the Kinetic Energy of electrons emitted from a metal is constant for all emitted electrons if the metal is subjected to a constant frequency of light that is higher than the threshold frequency of the metal. Initially I felt that the electrons have different...

Homework Statement I was just wondering that when I have a graph of the Stopping Potential versus Frequency of the light. How can I find the value for the cutoff frequency? Wavelength Vo 160 nm 2.99 V 53 nm...

Homework Statement 1. If frequency is constant and intencity of light is doubled what happen to the current? 2. If frequency is constant and intencity of light is doubled what happen to the voltage? 3. If intencity is constnat and frequency of light is doubled what happen to the current...

Homework Statement Calculate the wavelength of a photon having the same momentum as an electron moving at 1.0  106 m/s. The answer is supposed to be 0.73 nm. Homework Equations Ek = (m*v^2)/2 Ek = hf - W p = E/c = hf/c = h/\lambda The Attempt at a Solution I first found Ek using...

So what has to be right for a metal to release electrons when shot with a light? if you use more than what's needed will it still work? can this be used to power something? what else should i know about it? I want to buy some 5mm LED bulbs to mess around with. from my understanding you can make...

Homework Statement Assume that a point source of light gives 3 watt = 3 J/s of light energy. a) assume uniform radiation in all dirrections, find the light intensity in ev/m2*s b)Assuming some reasonable size for an atom, **** the energy/time incident on the atom for this intensity.Homework...

does anyone know what the minimum frequency actually is that the light needs to be in order for photons to be emmited? also, is there a point where if the frequencies too high, does THAT = no electron emmision? that is all!

does increasing the intensity of the light lower the threshold frequency at which photons knock off electrons?

Homework Statement When monochromatic light is incident on a metla plate,electrons are emmited only when the frequency of light exceeds a certain frequency. Explain in terms of energy, why this threshold frequency exist and why photon theory of light provides a better explnation of the...

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...

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

Hey I'm doing a 2 part project. The first part is the photoelectric effect, which I need some help on. I need a foil of metal (like aluminum foil but less of a work function) and a source of energy waves (UV or violet light probably). I need the combo of light source to generate a photoelectric...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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

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...

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...

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...

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...

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...

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...

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...

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...

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...

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?

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...

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...

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

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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?

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.

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 Φ=hf0...

[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...

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.