Photoelectric effect Definition and 385 Threads

Homework Statement A beam of light of 300nm is shone at a metal surface of work function 2.25eV. The power of the light striking each square centimeter is 1 microW. A total of 3cm^2 is illuminated by the beam. If each photon caused an electron to be ejected, what current is produced...

The answer key says the 450 nm (blue) light would make electrons with the most KE, which I get. But then it says that the yellow 560 nm light would shed more electrons, which makes no sense to me because I thought the # of e- only depended on the intensity of the light and the question says the...

This is not a specific question; I'm just unclear about a concept. Homework Statement Given the kinetic energy of an electron emitted, how would you find the wavelength? Homework Equations E=h*frequency or E=0.5mv2 The Attempt at a Solution I'm thinking I would use the...

A peak in the energy spectrum is seen at 134.2 keV when using a germanium detector. In coincidence with this, an x-ray corresponding to the 2s to 1s electronic transition in germanium is detected. Find the energy (in keV) of the gamma ray that ejected the electron. Use Rydberg's formula for...

Homework Statement Given two photocells, using light sources with identical frequency and intensity, but with different metal anodes with different work functions. Which of the followings are correct: A. The stopping voltage will be identical in both cells B. The current will be...

Homework Statement Is it possible for a gamma ray to interact with a free electron by mean of the photoelectric effect? Homework Equations The Attempt at a Solution I'm not really sure. I think the answer is no simply because of the mechanics of the photoelectric effect, i.e...

Electromagnetic radiated fields have both E and H fields perpendicular to the wave vector k. Therefore in photons the electric and magnetic fields are also perpendicular to k. This means that when photons are absorbed by some electron, the Lorenz Force will be mostly perpendicular to the...

Help!photoelectric effect Hi guys, for an electron to jump from a lower energy to a higher energy state, it must absorb photons that correspond to the difference of the these 2 enegry states. I am wondering if it is okey for an electron to absorb greater frequency of photons(greater energy) to...

I have a question, why does light act like a particle during the Photoelectric Effect Experiment, but acts as a wave in Thomas Young's Double Slit Experiment? Does anyone have a good book that I could rent in the Library or find on Questia.com or find online that I could use to read up on this?

It seems to me that the eyes are an example of the photoelectric effect at work. If so, which is more effective; current technology, photosynthesis, or our eyes?

Hi, I'm a newbie starting to study physics on my own (at a later age (45)). I've tried to find an answer to my question in this forum, the internet , books, etc... already. I'm reading Modern Physics, Tipler & LLewelyn. On p. 139 he presents a diagram illustrating Millikans experiment on...

Hi, I'm a newbie starting to study physics at a later age (45). I've tried to find an answer to my question in this forum, the internet , books, etc... already. I'm reading Modern Physics, Tipler & LLewelyn. On p. 139 he presents a diagram illustrating Millikans experiment on work function...

The wikipedia page on photoelectric effect http://en.wikipedia.org/wiki/Photoelectric_effect talks of a 5th experimental result, which I hadn't heard before: "The direction distribution of emitted electrons peaks in the direction of polarization (the direction of the electric field) of the...

Does anyone know how to determine the maximum photocurrent that could be produced by ejected electrons in a photoelectric effect experiment_(as unpolarized beam of light incidents on a metal surface)? I don't know of any formula that calculates the photocurrent and I could not derive any. I...

Homework Statement A photon of wavelength 250 nm ejects an electron from a metal. The ejected electron has a de Broglie wavelength of 0.85 nm. (a) Calculate the kinetic energy of the electron. Homework Equations KE = .5mv^2 The Attempt at a Solution Which answer is correct...

If a substance is warmer, is it easier for it to emit photoelectrons? I was thinking that maybe light of lower frequency would be required.

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...

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

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...

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...

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

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...