Photoelectric Definition and 426 Threads

Homework Statement I am trying to plot a graph of stopping voltage against frequency The given equation is eV0 = hf - w0 So i need to change it to the form of y = mx + C in order to plot this graph V0 = h*f/e - w0/e V0 = h/e * f - w0/e -- > V0 = y , m(gradient) = h/e , x= f and -w0/e = C (y...

In my book it is stated.When you keep the intensity constant and decrease the wavelength the photoelectric current decreases but I can't understand why? I thought it would stay the same since photoelectric current depends on the intensity of photons as more number oh photons means more e- released

Homework Statement A photon with of 13600eV energy interacts with a hydrogen atom at rest and ejects the electron (photoelectrically) in the direction in which the photon was travelling. If 13.6 eV is required to eject the electron, find the speed of the photoelectron and the momentum and...

Homework Statement I'm trying to determine Planck's Constant through an experiment with the Photoelectric Effect, however, the equations I'm given and the data I've collected are not getting me to the 6.63e-34 that I need to be at. I'm graphing Stopping Potential (V) vs 1/λ and then using the...

Recently I've seen claims here on PF(from some highly trusted members), that photoelectric effect can be described without using the photon concept and so can't be a demonstration of the quantized nature of light. This demonstration is only provided by more advanced experiments. After that, I...

Homework Statement "During a laboratory experiment with photoelectric effect, a metal plate is irradiated with light. The voltage that completely stops the beam of electrons is then measured. When the wavelength is 546 nm, the voltage is 0,38 V. When the wavelength is 410 nm, the voltage is...

Homework Statement In the photoelectric effect, it is assumed that a single electron absorbs a single photon. But, there is a certain probability that a single electron may simultaneously absorb two identical photons from a high-intensity laser. How would such an occurrence affect the...

I understand that intensity is power per unit time and that ##I = 2π^2f^2x^2_oρv## for regular waves (I don't know if the formula applies to E.M. waves or not). What I don't understand is why electrons are only released when the electromagnetic radiation incident on the metal surface is beyond...

Homework Statement Find the speed of light using Planck's constant measuring apparatus Homework Equations E=h(frequency) E=(h*c)wavelength The Attempt at a Solution Can I substitute E=mc2 and use the mass of electron in the equation?

I'm not really sure where to put this question, but definitely this is just an introductory physics coursework. Let me refresh you first with the basics of the photoelectric effect. We all know that in the photoelectric effect the stopping voltage is just the kinetic energy obtained by the...

Homework Statement If I know the work function of various metals in eV and need to find the largest wavelenghts required to emit photoelectrons from the metals would i just use ɸ=hf0=hc/λ0? Homework Equations ɸ=hf0=hc/λ0 The Attempt at a Solution The formula only gives the threshold...

From the post https://www.physicsforums.com/threads/photoelectric-effect-saturation-current.720506/ and http://www.thephysicsforum.com/quantum-physics/3921-photoelectric-current-dependence-potential-difference.html I have some idea on why does a higher potential different will not increase the...

Homework Statement I am doing the photoelectric effect experiment. And we were trying to verify the relationship between photoelectric current and distance is I \times d^2 = k, where k is a constant.(At least I believe this to be true.) But from the data, I kind of get a I= k d^{-2} + b . And...

When a cm thick surface is illuminated with light of wavelength lambda,the stopping potential is V. When the same surface is illuminated by light of wavelength 2lambda , the stopping potential is V/3.The threshold wavelength for the surface is ? Homework EquationsThe Attempt at a Solution

I was recently taught that the probability of the photoelectric effect occurring was proportional to Z^3 and E^-3 (where Z is the atomic number, and E is the energy of the photon). My understanding is that the photon's energy must be close to the binding energy of the inner electron to be...

Homework Statement In an photoelectric effect experiment , a photoelectric current of 100µA is obtained when lights of 550nm is incident on metal cathode of surface area 1.0cm^2 ... calculate the intensity of the incident light. The ans is 2.26w/m^2 Homework EquationsThe Attempt at a Solution...

Hi, how could i calculate the current I would get from the photoelectric effect, so that the end result would be in amps? If I have a certain lightsource or source of powerful enough em radiation to conduct the photoelectric effect , how could I calculate the intensity needed for given current ...

I want to understand how this circuit demonstrating the photoelectric effect works. Please see attached picture. On the picture we see light entering the cathode C, which, if the light is above the threshold frequency can eject electrons from the cathode, which hits the anode A, creating a...

What are the possible systematic/random error that can affect my experimental results?

Does the intensity of light mean increase no. of photons?

When a fixed intensity and frequency Em radiation strike a metal plate , is the outgoing electron/s with a higher energy if the plate is charged to some potential (volts) than if the plate is simply neutral?

Hi, I am currently revising photoelectric effect, and i have this question: A metal surface at zero potential emits electrons from its surface if light of wavelength of 450 nm is directed at it but not if light of 650nm is used. Explain why photoelectric emission happens with light of...

Homework Statement Which of the following best summarizes how a photoelectric detector provides an energy measurement: Answer choices: A) As light of multiple colors falls on the detector, the detector measures the energy of just one frequency of light by having a hole of only one...

In a photoelectric cell, the stopping voltage is 2.00V. If the voltage applied across this cell is zero, what is the maximum speed of the electrons from the photoelectric surface? Confused.

Homework Statement With the work function of copper being 4.65eV calculate the kinetic energy of a photoelectron knocked out with a photon with wavelength of 200nm . Then calculate the velocity of the electron.Homework Equations KE=hf-ø The Attempt at a Solution FIrst time I have done a...

Hi, I have read that light could either behave as waves or particles but not both at the same time. What will happen if we perform the diffraction experiment, but replace the screen with a metal whose work function is small enough so electrons could be ejected from the metal? Do we see...

First of all, Hi we haven't even learned the E = ((hc)/λ) in the physics class but we have this question on our test-exam and I hope that it's fairly easy: Homework Statement A metal plate is shone upon with a monochromatic light. When the wave-length is 550 nm a photo-electric effect is...

Hey guys, thanks for any help in advance. I'm working through some exercises in University Physics 13th Edition and have an issue with a photoelectric effect question. I'm given a graph that represents stopping potential as a function of frequency of light falling onto the surface (attached is...

Homework Statement Assume the same set-up to measure the stopping potential Vs through different filters. Suppose a filter allowed through only light of frequency fo (the cut-off frequency) or lower. In this case, what would the stopping potential be? 1) you cannot tell, since different...

Homework Statement Suppose the following: the light source gets very hot (by increasing the intensity), what affect do the heated photons have on photoemission? Possible choices: 1) they decrease the number of photoelectrons by heating the metal and raising the work function 2) none...

Homework Statement Suppose a filter allowed through only light of frequency fo (the cut-off frequency) or lower. In this case, what would the stopping potential be? Homework Equations KEmax = (charge of electron)(stopping potential) = hf - Work function, where Work function = hfcutoff...

Grade 12 physics help. Any help would be greatly apprecitated. Thanks 1. A light source with a wavelength of 550 nm shines on photocells, each with a work function of 1.60 eV. What is the minimum number of photocells required to generate 5.25 ´ 10-19 J of energy? 2. Light with a frequency...

Hello all, I have been searching the internet for quite some time now, and have been unsuccessful in finding some article that will explain WHY there is a saturation current. All I have found is the definition of the saturation current. I don't understand why the current becomes constant as...

Homework Statement I'm trying to make sense of some data taken during a lab in which we were tasked with obtaining a value for Planck's constant by measuring different stopping voltages from varying wavelengths of light. The value I got was 3E-15 eV*s, but I know I can get a better value if I...

Hi. The problem is the following: I have 2.5×10^{15} photons inciding every second on a photoelectric cell. Each photon has 2.5eV of energy and the work function of the cell is 2.2eV. I know that the photoelectric conversion efficiency is 20% and I'm asked to find the maximum electric current...

Hi all, I have a total of 6 questions, 3 of them are posted here and 3 of them are provided in the link because they involve graphs. 1. KE of an electron is twice that of a proton, what is ratio of de broglie wavelength of proton:electron? My answer: since de broglie wavelength is lamba =...

I've been reading through the posts on this forum that deal with the photoelectric effect as evidence for the quantization of the EM field. In all of the introductory texts I've read, the cut off frequency and the dependence of the photoelectron energy on the frequency of the light are...

Homework Statement Mmmm... Me and my classmate came across with this problem when studying photoelectric effect... Given a photocell connected to a circuit with a variable resistor (with resistance R) and an ideal ammeter. When a monochromatic light with frequency (f) (f>f0) and intensity...

Homework Statement I am wondering, what happens to those photons ( all having same energy level) in a light beam when the photons don't have enough energy to release the electrons in the metal that are more tightly attracted? Does the overall work function of the material decrease...

Homework Statement When 445 nm light strikes a certain metal surface, the stopping potential is 70% of that which results when 410 nm light strikes the same metal. Homework Equations The Attempt at a Solution $$P=0.7P'\\ \frac { nE }{ t } =\frac { 0.7nE' }{ t } \\ \frac { hc }{...

hi... i found a number of similar thread posing the same question but i didn't get the answer i was looking for, so i am asking it again. Basically, as far as i have understood photoelectric effect is about absorption of a photon by an electron and the extra energy converted to its kinetic...

Homework Statement So I recently performed the photoelectric effect experiment in my physics class, where we measured the stopping voltage at different wavelengths of light by using filters with different levels of grating. I measured the stopping voltage and plotted them on a graph against...

Textbooks say that by measuring the stopping potential V0, we can determine the maximum kinetic energy with which electrons leave the cathode: eV0 = Kmax However, as I know, when we apply the stopping potential, the electrons will decelerate and radiate parts of their energies. Thus, the...

Homework Statement Lets say we have a silver ball with radius ##r=1cm## hanging on a string which is an isolator. What is a charge on the ball if we shine on it with a light with ##\lambda = 200nm##? The work function for silver is ##A_0 = 4.7eV##.Homework Equations \begin{align} &W - A_0 = W_k...

Provide one of the following answers: PE,CS, BOTH, OR NEITHER. PE if the statement applies only to Photoelectric Effect. CS if the statement applies only to Compton Scattering BOTH if the statement applies only to both the Photoelectric Effect and Compton Scattering. NEITHER if the...

Homework Statement The graph in fig shows the stopping potential as a function of the frequency of the incident light falling on the metal surface. Find the photoelectric work function for this metal Homework Equations V_0 =\frac{hf}{e}-\frac{\phi}{e} The Attempt at a Solution...

If I write photoelectric effect equation to nhv = 1/2mv2 + W with n = 1, I am puzzled whether the n is larger than 1, such as 2 or 3, for which I will get the two- or three- photon absorption. Could you give me some comments on these question? Best regards. sandf

I had a lab with photoelectric effect and we measured different colors wavelength/frequency by finding stopping voltage vs current. Then we used no color filter and used the mercury vapor lamp and had to find the wavelength which was around 400nm. Questions were why was this wavelength the...

what is the relationship between frequency and kinetic energy max ?

Hello Here is the problem I am trying to solve. Find the maximum kinetic energy of the photo electron liberated from the surface of lithium by electromagnetic radiation whose electric component varies with time as E=a(1+\cos \omega t)\;\cos(\omega_0 t) where a is constant and \omega =...