मराठी
महाराष्ट्र राज्य शिक्षण मंडळएचएससी विज्ञान (सामान्य) इयत्ता १२ वी

Explain the inverse linear dependence of stopping potential on the incident wavelength in a photoelectric effect experiment. - Physics

Advertisements
Advertisements

प्रश्न

Explain the inverse linear dependence of stopping potential on the incident wavelength in a photoelectric effect experiment.

थोडक्यात उत्तर
Advertisements

उत्तर

When a beam of light of a specific wavelength (or frequency) strikes the metal's surface, the total number of electrons ejected and the kinetic energy of each electron is given by,
K.Emax ​= `"hc"/lambda - phi,`
Where, V0​ is stopping potential.
So, `"V"_0"e" = "hc"/lambda - phi,`
where V0 is the stopping potential, e is the charge magnitude on the electron, h is Planck's constant, c is the speed of light in free space, λ is the wavelength of the electromagnetic radiation incident on a metal surface and Φ is the work function for the metal, h, c and e are constants. For a specific metal, Φ is constant.

Hence, it follows that as `1/lambda` increases, V0 increases.
The plot of V0 verses `1/lambda` is linear. This is due to the fact that the energy associated with a quantum of radiation (photon) is directly proportional to its frequency and thus inversely proportional to its wavelength of radiation.

shaalaa.com
The Photoelectric Effect
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 14: Dual Nature of Radiation and Matter - Exercises [पृष्ठ ३२२]

APPEARS IN

बालभारती Physics [English] Standard 12 Maharashtra State Board
पाठ 14 Dual Nature of Radiation and Matter
Exercises | Q 3 | पृष्ठ ३२२

संबंधित प्रश्‍न

What is the photoelectric effect?


Radiation of wavelength 4500 Å is incident on a metal having work function 2.0 eV. Due to the presence of a magnetic field B, the most energetic photoelectrons emitted in a direction perpendicular to the field move along a circular path of radius 20 cm. What is the value of the magnetic field B?


The electrons are emitted in the photoelectric effect from a metal surface.


As the intensity of incident light increases ______ 


Planck's constant is 6.6 × 10-34 Js. The momentum of each photon is given radiation Is 3.3 × 10-29 kg/s. The λ of radiation is ______.


With the help of a circuit diagram describing an experiment to study the photoelectric effect.


The work function of a surface is 3.1 eV. A photon of frequency 1 × 1015 Hz. Is an incident on it. Calculate the incident wavelength is photoelectric emission occurs or not.   


State Einstein’s photoelectric equation. Explain all characteristics of the photoelectric effect, on the basis of Einstein’s photoelectric equation.  


The maximum velocity of the photoelectron emitted by the metal surface is v. Charge and the mass of the photoelectron is denoted by e and m, respectively. The stopping potential in volt is ______.


Threshold wavelength for lithium metal is 6250 Å. For photoemission, the wavelength of the incident light must be ______.


A metal surface is illuminated by photons of energy 5 eV and 2.5 eV respectively. The ratio of their wavelengths is ____________.


Light of frequency 2 times the threshold frequency is incident on a photo sensitive material. If the frequency is made `1/3`rd and intensity is doubled then the photocurrent will ______.


The photo electric effect to take place for a metal, the minimum frequency required is 5.792 × 1014 Hz. A light of wavelength 6000 Å is incident on that metal surface. What is the corresponding frequency of light and will there be photoelectric emissions? [velocity of light = 3 × 108 m/s]


When a surface 1 cm thick is illuminated by light of wavelength 'λ', the stopping potential is 'V0'. When the same surface is illuminated by light of wavelength '3λ', the stopping potential is `"V"_0/6`. The threshold wavelength for the metallic surface is ______.


Light of different frequencies, whose photons have energies 3 eV and 18 eV respectively, successively illuminate a metal of work function 2 eV. The ratio of the maximum speeds of the emitted electrons will be ______.


Which one of the following statements ts INCORRECT for stopping potential in photoelectric emission?


The radiations of energies 1 eV and 2.5 eV are incident on a metal surface having work function 0.5 eV. The ratio of the maximum velocities of the emitted photo-electrons is ____________.


In experiment of photoelectric effect, the stopping potential for incident yellow light of wavelength 5890 Å is 4 volt. If the yellow light is replaced by blue light of wavelength 4000 Å, the stopping potential is ____________.


The wavelength of light incident on a metal surface is reduced from 300 nm to 200 nm (both are less than threshold wavelength). What is the change in the stopping potential for photoelectrons emitted from the surface will be ______ V. (Take h = 6.6 × 10-34 J-s)


The maximum kinetic energy of the photoelectrons ejected will be ______ eV when the light of wavelength 350 nm is incident on a cesium surface. The work function of cesium = 1.9 eV.


A point isotropic light source of power P = 12 watts is located on the axis of a circular mirror of radius R = 3 cm. If the distance of the source from the centre of the mirror is a = 39 cm and the reflection coefficient of the mirror is α = 0.70 then the force exerted by the light ray on the mirror is ______ × 10-10 N.


If the electron in hydrogen atom jumps from second Bohr orbit to ground state and difference between energies of the two states is radiated in the form of photons. If the work function of the material is 4.2 eV, then stopping potential is ______.

[Energy of electron in nth orbit = `-13.6/"n"^2` eV ]


Light of wavelength λ, which is less than threshold wavelength is incident on a photosensitive material. If incident wavelength is decreased so that emitted photoelectrons are moving with same velocity, then stopping potential will ______.


The following graphs show the variation of stopping potential corresponding to the frequency of incident radiation (ν) for a given metal. The correct variation is shown in graph [ν0 = threshold frequency].

(A)

(B)

(C)

(D)


Light of two different frequencies whose photons have energies 1.3 eV and 2.8 eV respectively, successfully illuminate a metallic surface whose work function is 0.8 eV. The ratio of maximum speeds of emitted electrons will be ______.


The photoelectric threshold for a certain metal surface is 3600 Å. If the metal surface is irradiated by a wavelength of 1100 Å, then kinetic energy of the emitted photoelectrons is ______.


If the maximum kinetic energy of emitted electrons in the photoelectric effect is 2eV, the stopping potential will be ______.


The threshold frequency for a certain metal for photoelectric effect is 1.7 x 1015 Hz. When a light of frequency 2.2 x 1015 Hz is incident on the metal surface, the kinetic energy of the emitted photoelectrons is 3.3 x.10-19 J. Calculate Planck's constant.


Explain the formation of clouds at high altitude.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×