Photoelectric Definition and 426 Threads

Homework Statement "The threshold frequency of a particular metal surface is 5.6 × 1014 Hz. Calculate the maximum kinetic energy of emitted electrons if the frequency of the light striking the metal surface is double the threshold frequency." Taken from AQA Physics Exam 2009 Homework...

It puzzles me. In Einstein's paper on the photoelectric effect he proposed that photons with E = nhf were the explanation. Wouldn't a more elegant explanation be that the tangent of the electromagentic wave must take on discrete values because of the boundary conditions between the emitter...

This is more of a conceptual question. Homework Statement -------------------- 1.KE_{Max} = hf-\phi 2.\phi = Work Function. The minimum energy required to free an electron with a photon 3.E=hf This it the energy of a photon --------------------- In my book it says that" hf > \phi"...

Homework Statement In a photoelectric-effect experiment, light of wavelength (x) nm is incident on a sample of sodium. The work function of sodium is (y) J. Calculate the stopping potential required to just stop all electrons from reaching the anode. Homework Equations To work out...

HELP! photoelectric effect Ok guys got a question on quantum physics - photoelectric effect i want to run past you before i attempt a solution. The question is as follows; In a photoelectric-effect experiment, light of wavelength 420nm is incident on a sample of sodium. The work function...

Homework Statement Which of the following statements about the photoelectric effect are true? -(T/F) The number of emitted electrons depends on the frequency, not the number of photons. -(T/F) The radiation needs a minimum number of photons for any electrons to be released. -(T/F) The...

Ok guys got a question on quantum physics - photoelectric effect i want to run past you before i attempt a solution. The question is as follows; In a photoelectric-effect experiment, light of wavelength 420nm is incident on a sample of sodium. The work function of sodium is 3.67*10-19 J...

Homework Statement What potential difference must be applied to stop the fastest photoelectrons by a nickel surface under the action of ultraviolet light of wavelength 220 nm? work function of nickel is 5.00eV.Homework Equations h[c]/[\lambda] = \Phi + eVThe Attempt at a Solution h=6.6x10^-34...

The theory I have read When you charge an electroscope with a negatively charged rod, electrons are repelled to the bottom of the electroscope and the gold leaf rises. Then when you shine light above the fundamental frequency on the top plate of the electroscope, electrons are liberated from...

Hi there, Im having a problem with the results I am getting for an experiment I am doing in relation to the photoelectric effect. My graph is very similar to that in the attachment, except for the fact that the line at A and again after the drop is sloping at a very steep angle to begin...

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...

Hey all, can anyone answer this question?? according t einstein's theory on photoelectric effect if the photon's energy is less then the work function of the material, electron can not come out... My question is: what happens when a lower energy(less then work function of a material)...

I wonder why the thread on Lamb's paper was locked? I was hoping to take part in the discussion.

Lamb and "The Photoelectric Effect Without Photons" I've recently been pointed by two different people to this paper by Lamb (yes, that Lamb) and Scully: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19680009569_1968009569.pdf . The title is "The Photoelectric Effect Without Photons."...

Homework Statement The work function of chromium metal is 7.2 x 10-19 J. What is the maximum speed an electron can be moving if it is ejected from chromium metal by light of wavelength 250 nm? (Answer: u= 4 x105 m/s) Homework Equations \Phi = h v_{0} KE = h v_{light} - \Phi =...

In the photoelectric effect, if you have a frequency above the threshold frequency, electrons are ejected with greater kinetic energy, but the voltage and current of a circuit using the photoelectric effect is the same. If electrons have a greater Ek, they would have a greater speed, and so if...

It is known that for light of a given intensity when incident on a photoelectric material, the number of electrons emitted is independent of the frequency of light, but increases when the intensity of light goes up. However, the maximum kinetic energy of the emitted electrons increases with the...

Hi When a photon of insufficient energy (lower that the metal's work function) arrive on the metal's surface, what will happen? One part of my notes says that it will be "reflected with no loss of energy", but my teacher has recently stated that it will be absorbed and emitted back as...

Homework Statement When 520nm light falls on a metal, the current through the circuit is brought to zero by a reverse voltage of 1.13V. What is the threshold frequency for this metal. Homework Equations E = h.f The Attempt at a Solution Using the above formula I get an threshold...

Homework Statement What is the maximum energy of the ejected electrons? When the radiation wavelength is 100 nm, and the stopping potential of the metal is 8. Homework Equations KE = hc/wavelenght - Wo The Attempt at a Solution I found the work function and the cut off wavelength...

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...

Suppose you have a solar sail that was capable of perfect photoelectric conversion. So this means that photons from the Sun are striking your solar sail, and also being photoelectrically converted to electrical current. My question is - does the photoelectric conversion at all affect the...

I have a few questions on the Photoelectric Effect. First off, what wavelengths could be used to cause a photoelectric on Stainless Steel? What widely available metals have the lowest eV for the photoelectric effect? Could a UV light of 380nm work to cause a photoelectric effect on...

Homework Statement The efficiency of electron excitement by photons is described as being related to how much different orbitals share the same k-space or momentum space. Is this similar to orbital shape (eg spheres, dumbells, ec)? Homework Equations The Attempt at a Solution I...

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 was posting on another thread and it got me wondering: how come a photon is absorbed in the photoelectric effect but it is only partially absorbed in the Compton Effect? How come the electron in the Compton Effect does not absorb the photon entirely like the photoelectric effect? If photon is...

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...

Homework Statement Suppose that 2 identical photoelectric devices are connected to the same electrical circuit, and the devices are connected in parallel with each other. Compared to the voltage generated by a single device, the total voltage supplied by the parallel devices will be...

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.

Hey there, I know this may seem like a stupid question but what is the relationship between the maximum electric current and the intensity of light? :)

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 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...