English

State Einstein photoelectric equation.

Advertisements
Advertisements

Question

State Einstein photoelectric equation. 

Derivation
Advertisements

Solution

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
  Is there an error in this question or solution?
Chapter 14: Dual Nature Of Radiation And Matter - Short Answer II

APPEARS IN

SCERT Maharashtra Physics [English] Standard 12 Maharashtra State Board
Chapter 14 Dual Nature Of Radiation And Matter
Short Answer II | Q 1. (i)

RELATED QUESTIONS

What is the photoelectric effect?


Observations from an experiment on the photoelectric effect for the stopping potential by varying the incident frequency were plotted. The slope of the linear curve was found to be approximately 4.1 × 10−15 V s. Given that Exercises the charge of an electron is 1.6 × 10−19 C, find the value of the Planck’s constant h.

Given the following data for incident wavelength and the stopping potential obtained from an experiment on the photoelectric effect, estimate the value of Planck's constant and the work function of the cathode material. What is the threshold frequency and corresponding wavelength? What is the most likely metal used for emitter?

Incident wavelength (in Å) 2536 3650
Stopping potential
(in V)
1.95 0.5

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


Explain the concept of the photoelectric effect. 


The energy of a photon is 2 eV. Find its frequency and wavelength.  


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.   


With the help of a circuit diagram describe the experiment to study the characteristics of the photoelectric effect. Hence discuss any 2 characteristics of the photoelectric effect.  


The maximum velocity of photoelectron emitted is 4.8 m/s. If the e/m ratio of the electron is 1.76 × 1011 C/kg, then stopping potential is given by ______ 


When a photon enters glass from air, which one of the following quantity does not change?


The graph of stopping potential `"V"_"s"` against frequency v of incident radiation is plotted for two different metals P and Q as shown in the graph. ΦP and ΦQ are work-functions of P and Q respectively, then


When light falls on a metal surface, the maximum kinetic energy of the emitted photoelectrons depends upon ______


If the maximum kinetic energy of emitted electrons in photoelectric effect is 3.2 × 10-19 J and the work-function for metal is 6.63 × 10-19 J, then stopping potential and threshold wavelength respectively are
[Planck's constant, h = 6.63 × 1034 J-s]
[Velocity of light, c = 3 × 108 `"m"/"s"`]
[Charge on electron= 1.6 × 10-19 C]


A metal surface is illuminated by light of given intensity and frequency to cause photoemission. If the intensity of illumination is reduced to one-fourth of its original value then the maximum KE of the emitted photoelectrons would be ______.


Photoelectrons emitted from a metallic surface are initially ____________.


An important spectral emission line has a wavelength of 21 cm. The corresponding photon energy is (h = 6.62 x 10-34 Js, c = 3 x 108 m/s) ____________.


The threshold frequency for a certain photosensitive metal is v0. When it is illuminated by light of frequency v = 2v0, the maximum velocity of photoelectrons is v0. What will be the maximum velocity of the photoelectrons when the same metal is illuminated by light of frequency 

v = 5v0?


In photoelectric effect, for a light of different intensities but of same frequency, the stopping potential for a given metal is ____________.


When wavelength of incident radiation on the metal surface is reduced from 'λ1' to 'λ2', the kinetic energy of emitted photoelectrons is tripled. The work function of the metal is ______.
(h = Planck's constant, c =velocity of light)


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]


The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photo-emission from this substance is approximately (h = 6.63 × 10-34 Js)[1eV = 1.6 × 10-19 J]


The ratio of slopes m1: ro2 of the lines given in the following graphs is, ______.


The stopping potential in the context of photoelectric effect depends on the following property of incident electromagnetic radiation ______.


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 ______.


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 ______.


Give Einstein's explanation of the photoelectric effect.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×