Photoelectric effect Definition and 385 Threads

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...

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?

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...

[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.

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.

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...

I learn about photoelectric effect. Can somebody tell me why: eU_z=E_k_,_m_a_x What is eU_z?

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...

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

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...

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...

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...

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...

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...

Homework Statement In an xray tube, a potential diff. of 70000v is applied across two electrodes. Electrons are emmited from cathode and acc. to anode, where x-rays are produced. my question is if the photoelectric effect problems apply and how they apply. (i.e use work function or E=hf)...

Hi. I hope someone can help. Here is the problem: [Pennies are made of zinc coated with copper. Copper has a work function of 4.7eV. The ozone layer blocks nearly all solar radiation with wavelength shorter than 320nm, but a very small amount of 200nm light still manages to reach the Earth's...

Help on "Photoelectric Effect" problem a] A beam of light of wavelength 400nm and power 1.55mW is directed at the cathode of a photoelectric cell. If only 10% of the incident photons effectively produce photoelectrons, find the current due to these electrons. b]If the wavelength of light is...

I'm not sure if I'm posting this in the right forum, so I apologize in advance if I'm not. I just have a question about the photoelectric effect. As I understand it, the photoelectric effect is where light/photons can knock electrons off a metal surface. I think that the intensity of the light...

[SOLVED] Photoelectric effect, retarding potential Homework Statement If the photocurrent of a photocell is cut off by a retarding potential of 0.92 volts for monochromatic radiation of 2500 A (A with the little circle above it), what is the work function of the material. Homework...

Homework Statement Light of intensity 1.5 x 10 (x)-2 Wm/2 and wavelength 250 x 10 (x)-9m is incident on an iron surface of area 1 x 10 (x) -4 m2. The iron surface reflects 95% of the light. The threshold frequency for iron is 1.1 x 10x15 Hz. Calculate: 1) The intensity of light available for...

What property of light does the photoelectric effect display?

Homework Statement Having some problem with this question: The threshold fequency for a material is 5.0*10^14 Hz. Find (a) the work function and (b) the maximum velocity of electrons ejected by radiation of frequency 8.0*10^14 Hz. The mass of an electron is 9.1*10^-31kg. Homework...

Hi I'm a materials engineer and we have a subject about the optical and electrical properties of materials. In this subject I was asked a challenging question. I hope this is the right section for it. We were asked why gamma rays do not exhibit true absorbance in metals whereas ultraviolet...

Below is my understanding of photoelectric effect, please correct me if I am wrong. It is an quantum electronic effect in which matter emits electrons after receiving energy in the form of EM waves. E.g. imparting X-rays on matter. So if we impart a high frequecncy wave (say f1) on a metal...

Homework Statement What will be the electric charge of an isolated ball of copper, which was projected long enough with radiation of wavelength \lambda = 1400 \angstrom? Homework Equations The radius of the ball is R=1cm and the work function of copper is \Phi = 4.47 eV. The Attempt at...

The Question: Find the maximum momentum of the electrons emitted from the surface of the Li metal, under the projection of the metal with EM radiation, when the electric component of the radiation is a function of time: E(t) = a(1+cos[w*t])*cos[w0*t] a= 18 [V/m] w= 6E14 [1/sec] w0= 3.6E15...

1. Light of a wavelength 410nm is incident on a metal target and an electron is eject from the surface. The work required to remove this electron from the metal is 3.0 x 10^-19 J. The elctron then travels straight to a collection plate. The different in electric potential between the collector...

Hi all, I would really appreciate any explanation on how these two are interrelated. Thanks. Preferably in simple terms. Nish

I am having trouble figuring how the info given relates to electric and magnetic fields. Homework Statement A laser emits 1.38x10^18 photons per second in a beam of light that has a diameter of 1.96 mm and a wavelength of 518.0 nm. Determine each of the following for the electromagnetic wave...

Homework Statement From the following graph determine the experimental value of the h/e ratio and the work function of the metal. ( 1 Joule = 6.242 x 1018 eV ) https://chip.physics.purdue.edu/protected/Prelab221img/e9pp41.jpg The work function Wo in eV from the y-intercept of the...

A 0.4 kilogram sample of Aluminum at 115 degrees Celsius is put into a container containing 0.5 kilograms of water at 15 degrees Celsius. Neglecting the small amount of energy absorbed by the container and knowing that the specific heat of Aluminum is 900 kJ/kg*C, and the specific heat of the...

Let us consider the photoelectric effect described on http://hyperphysics.phy-astr.gsu.edu/hbase/mod1.html/" . A photon has an energy of 2.25 eV and produces a photoelectron effect on a potassium target, the maximum energy of the photoelectron is 0.50 eV, indicating the photoelectric...

Homework Statement 3. The classical radius of an electron is 2.82 x 10^-15 m. If a material is radiated with sunlight with an intensity of 500W/m^2, calculate using classical arguments the time required for an electron to gain an energy of 1eV. How does this result compare with electron...

Homework Statement In an advanced laboratory class a student performs the photoelectric experiment. Ultraviolet light is shone on a particular metal and the stopping potential is measured at the same time. It is found that 2.61 V is needed to stop all the electrons when the wavelength of the...

Homework Statement Light is incident on the surface of metallic sodium, whose work function is 2.3 eV. The maximum speed of the photoelectrons emitted by the surface is 1.08 106 m/s. What is the wavelength of the light? Homework Equations e=hf p=h/wavelength The Attempt...

Once electrons are ejected via photoelectric effect, the eventual recombination of the holes they leave behind is not discussed much (maybe not even at all) in textbooks. Also important, where they recombine as well as how long after the e-h pair formation.

Hiya, I'm about to teach the photoelectric effect in class. Everybody knows that observations contradict the classical prediction. Which is: Stopping voltage schould go up with light intensity. OK. But I have a problem: What EXACTLY is the classical prediction? I mean, is there a formula that...

The Photoelectric effect and "classical physics" The kinetic energy of the ejected electrons predicted by the classical physics should be related to the intensity of the light. According to experimental results, the kinetic energy of the electrons is proportional to the frequencies of the...

A sinusoidal EM wave which length l is very great, hits a photoelectric device. According to HUP, a sinusoidal EM wave with finite length l has a spectrum of frequencies which broadness is inversely proportional to l. So, if l is very great, the energy uncertainty is very low, and this, still...

:confused: why can't wave nature of light explain photoelectric effect?

Light is incident on the surface of metallic sodium, whose work function is 2.3 eV. The maximum speed of the photoelectrons emitted by the surface is 1.26e6 m/s. What is the wavelength of the light? I first converted Work Function to Joules: 2.3eV x (1.6e-19 J / 1eV) = 3.68e-19 J The...

White light (ranging in wavelengths from 380 to 750 nm) is incident on a metal with work function Wo = 2.46 eV. (a) What is the maximum kinetic energy of the electrons emitted from the surface? KEmax = eV E = hf = hc/lamda. E = (6.626*10^-34)(3*10^8) / (750*10^-9) = 2.6504E-19...

What is the main differences? Are they essentially the same thing? From what I have gathered, the two are fundalmentally the same. If a photon gives up all its energy after interaction with an electron than the photoelectric effect applies. On the other hand if the photon continues to travel...

Hello my question involves what exactly is the frequency and intensity of the light. The E = hf applies to the photon particle aspect of light right? So where is f from, the wave aspect? Also increase f, which increases E makes the electrons eject faster in terms of kinetic energy right, but...

Hi guys, I've got a little conceptual question here. I became a little confused after my exam. Firstly, I understand that in the photoelectric effect, the electrons either accept all or none of the energy from the particular incident photon and the photon must have a minimum frequency...

Hi guys, I've just returned from my exams.. I thought it was pretty alright but I think it could've been better. I was stuck with this question. A photoelectric experiment was set up. Monochromatic light is incident on a metal plate, and the photo-electrons are collected at a electrode...