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

State Einstein photoelectric equation. - Physics

Advertisements
Advertisements

प्रश्न

State Einstein photoelectric equation. 

व्युत्पत्ती
Advertisements

उत्तर

K.E.max = `(hν - phi_0)`

or K.E.max = (hν – hv0)     

or `1/2 mv_(max)^2 = hv - hv_0`

where, (K.E.)max → Maximum kinetic energy

= `1/2 mv_(max)^2`

`phi_0` Photoelectric work function = hv0

h → Planck’s constant

v → Frequency of radiation

v0 → Threshold frequency

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 14: Dual Nature Of Radiation And Matter - Short Answer II

APPEARS IN

एससीईआरटी महाराष्ट्र Physics [English] 12 Standard HSC
पाठ 14 Dual Nature Of Radiation And Matter
Short Answer II | Q 1. (i)

संबंधित प्रश्‍न

It is observed in an experiment on the photoelectric effect that an increase in the intensity of the incident radiation does not change the maximum kinetic energy of the electrons. Where does the extra energy of the incident radiation go? Is it lost? State your answer with explanatory reasoning.


Photocurrent recorded in the microammeter in an experimental setup of the photoelectric effect vanishes when the retarding potential is more than 0.8 V if the wavelength of incident radiation is 4950 Å. If the source of incident radiation is changed, the stopping potential turns out to be 1.2 V. Find the work function of the cathode material and the wavelength of the second source.


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?


Draw a neat labelled diagram of a schematic of the experimental setup for the photoelectric effect. 


Explain the concept of the photoelectric effect. 


Which one of the following is TRUE in photoelectric emission?


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


For photoelectric emission from certain metal, the cut-off frequency is v. If radiation of frequency 2v impinges on the metal plate, the maximum possible velocity of the emitted electron will be (m is the electron mass) ____________.


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


In photoelectric effect, graph of saturation current versus frequency of light is plotted. The nature of the graph will be ____________.


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 ______.


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 ______.


The photon of frequency vis incident on a metal surface whose threshold frequency is v0. The kinetic energy of the emitted photoelectrons will be ______.


When a certain metallic surface is illuminated with monochromatic light of wavelength '`lambda`', the stopping potential for photoelectric effect is '3V0'. If the same surface is illuminated with a light of wavelength '`2 lambda`', the stopping potential is found as 'V0'. The threshold wavelength for this surface is ____________.


The ratio of slopes m1: ro2 of the lines given in the following graphs 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 ____________.


When the work function of a metal increases, maximum kinetic energy of emitted photoelectrons ____________.


Is it always necessary to use red light to get a photoelectric effect?


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 charged dust particle of radius 5 × 10-7 m is located in a horizontal electric field having an intensity of 6.28 × 105 V/m. The surrounding medium is air with a coefficient of viscosity η = 1.6 × 10-5 N-s/m2. If the particle moves with a uniform horizontal speed of 0.02 m/s, the number of electrons on it is ______.


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 ]


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)


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 ______.


When monochromatic light of frequency v1 falls on a metal surface, the stopping potential required is found to be V1. If the radiation of frequency v2 is incident on the surface, the stopping potential required V2 is ______. (v2 > v1)


By increasing the voltage in an electron diffraction tube, the radius of the diffraction rings will ______.


Draw a neat labelled diagram of photo-current as a function of accelerating potential for fixed incident intensity but different incident frequencies for the same emitter material.


In a photoelectric experiment, the stopping potential is 1.5V. What is the maximum kinetic energy of a photoelectron?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×