Work Function And Threshold Frequency

The work function: The work function of a metal is the energy corresponding to the threshold frequency of the metal. The work function is usually denoted by the Greek letter φ. Albert Einstein used the work function of a metal to describe the photoelectric effect.

Is work function and threshold frequency same?

Work function can be directly applied to the Einstein equation of the photoelectric effect. To apply the threshold frequency, the frequency must be multiplied by the plank constant in order to obtain the corresponding energy.

What is photoelectric work function how it is related to threshold frequency?

The photoelectric work function is the threshold energy required by the radiation or photons that are incident on the surface of the metal. We can use the term radiation interchangeably with photons in this case. ϕ=hν0 where h is the Planck's constant and ν0 is the threshold frequency.

Is work function proportional to threshold frequency?

The threshold frequency is directly proportional to the work function and is given by f=E/h, where E is equal to Φ, f is the threshold frequency and h is Planck's constant. Providing the frequency of the photon is greater than the threshold frequency, the electron absorbing the photon will escape the material.

What is the relation between work function and threshold wavelength?

The frequency of the light for which its energy is equal to the work function is called threshold frequency ν0. Therefore, ϕ=hν0. Let us use the relation between the frequency and the wavelength of light, i.e. ν=cλ. When the light wave has threshold frequency, its wavelength is called threshold wavelength (λ0).

What is work function formula?

Since work function does not depend on wavelength of incident light so it will be constant for both cases. Thus, W=λ2hc−eVs1.

What do you mean by work function?

Definition of work function : the energy that is needed for a particle to come from the interior of a medium and break through the surface —used especially of the photoelectric and thermionic emission of electrons from metals.

What is work function threshold frequency and stopping potential?

Work function is the minimum amount of energy required to remove an electron to infinity, from the surface of a given metal. Threshold frequency is the minimum frequency of the incident light which can cause the ejection of electrons without giving them additional energy.

What is meant by threshold frequency?

The threshold frequency is defined as the minimum frequency of incident radiation below which the photoelectric emission is not possible completely. irrespective of the intensity of incident radiation.

Does work function depend on frequency?

Depends upon the frequency of incident light. Hint: The different metals consist of different values of work function because of difference in their electronegativity behaviour. Therefore the work function is that amount of energy which is required to get an electron out of the metal plate without any kinetic energy.

What does threshold frequency depend on?

Solution : The threshold frequency depends on the metal or material of the cathode.

What do you mean by work function related to photoelectric effect?

The photoelectric work function is the minimum photon energy required to liberate an electron from a substance, in the photoelectric effect. If the photon's energy is greater than the substance's work function, photoelectric emission occurs and the electron is liberated from the surface.

What is the formula of work function of metal?

The difference between the electron energy just outside the metal surface, Evac(s), and EF defines the work function of the metal surface, φm = Evac(s) - EF.

Is work function directly proportional to wavelength?

Thus, λ or threshold wavelength is inversely proportional to the energy or the work-function.

What is the threshold wavelength for A metal whose work function is 2.4 eV?

A metal has threshold wavelength of 6400 Å calculate.

What is the threshold wavelength for A metal whose work function is 4.8 eV?

Tungsten has work function 4.8eV , we wish to use tungsten as photo - cathode with a 600 nm wavelength .

What is the formula of threshold frequency?

E = hf = Φ + ½mv2max h = Planck's constant (J s) f = the frequency of the incident radiation (Hz) Φ = the work function of the material (J) ½mv2max= the maximum kinetic energy of the photoelectrons (J)

Why is it called work function?

We need additional energy for the removal of an electron to overcome the surface barrier of the metal is called the work function of the metal. The minimum energy required for an electron to just escape from the metal surface is called “work function”.

How is work function measured?

The work function is the minimum energy required to take out one electron through the surface. It can be measured by analyzing the slowest electrons emitted from the substrate applied with excess energy.

What is work function and its unit?

Work function is expressed in eV, and 1eV=1. 6×10−19 J. By definition, Electronvolt (eV) is the amount of energy gained (or lost) by the charge of a single electron moved across an electric potential difference of one volt.