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प्रश्न
What is the photoelectric effect?
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उत्तर
The phenomenon of the emission of electrons from a metal surface when electromagnetic radiation of the appropriate frequency is incident on it is known as the photoelectric effect.
संबंधित प्रश्न
Can microwaves be used in the experiment on photoelectric effect?
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.
The threshold wavelength of tungsten is 2.76 x 10-5 cm.
(a) Explain why no photoelectrons are emitted when the wavelength is more than 2.76 x 10-5 cm.
(b) What will be the maximum kinetic energy of electrons ejected in each of the following cases
(i) if ultraviolet radiation of wavelength λ = 1.80 × 10-5 cm and
(ii) radiation of frequency 4 x 1015 Hz is made incident on the tungsten surface?
The electrons are emitted in the photoelectric effect from a metal surface.
Find the kinetic energy of the emitted electron, if in photoelectric effect energy of incident Photon is 4 eV and work function is 2.4 eV.
If the total energy of radiation of frequency 1014 Hz is 6.63 J, Calculate the number of photons in the radiation.
With the help of a circuit diagram describing an experiment to study the photoelectric effect.
The energy of a photon is 2 eV. Find its frequency and wavelength.
The ratio of energies of photons produced due to transition of electron of hydrogen atom from its (i) second to first energy level and (ii) highest energy level to second level is respectively.
Which one of the following is TRUE in photoelectric emission?
The following graph shows the stopping potential V0 versus frequency v for photoelectric emission from two metals A and B. The slope of each of the lines gives ______
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
Threshold wavelength for lithium metal is 6250 Å. For photoemission, the wavelength of the incident light must be ______.
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?
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 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 ____________.
When light of wavelength '`lambda`' is incident on photosensitive surface, photons of power 'P' are emitted. The number of photons (n) emitted in 't' second is (h = Planck's constant, c = velocity of light in vacuum) ____________.
A metal surface having work function 'w0' emits photoelectrons when photons of energy 'E' are incident on it. The electron enters the uniform magnetic field (B) in perpendicular direction and moves in circular path of radius 'r'. Then 'r' is equal to (m and e be the mass and charge of electron respectively) ____________.
When the work function of a metal increases, maximum kinetic energy of emitted photoelectrons ____________.
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.
We wish to observe an object which is 2.5Å in size. The minimum energy photon that can be used ______.
For a given photosensitive material and frequency (> threshold frequency) of incident radiation, the photoelectric current varies with the intensity of incident light as:
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 ______.
If the maximum kinetic energy of emitted electrons in the photoelectric effect is 2eV, the stopping potential will be ______.
Explain the failure of wave theory of light to account for the observations from experiments on photoelectric effect.
Define photoelectric work function of a metal.
According to Einstein's photoelectric equation, the graph of kinetic energy of the photoelectron emitted from the metal versus the frequency of incident radiation gives a straight line graph whose slopе ______.
