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प्रश्न
What is the photoelectric effect? Define stopping potential and photoelectric work function.
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उत्तर
- The phenomenon of emission of electrons from a metal surface, when radiation of appropriate frequency is incident on it, is known as the photoelectric effect.
- If increasingly negative potentials were applied to the collector in the experiment of the photoelectric effect, the photocurrent decreases and for some typical value (– V0), photocurrent becomes zero. This value of V0 is termed as cut-off or stopping potential.
- The minimum amount of energy required to be provided to an electron to pull it out of the metal from the surface is called the work function of the metal.
संबंधित प्रश्न
If the frequency of incident light falling on a photosensitive material is doubled, then the kinetic energy of the emitted photoelectron will be ______.
The maximum kinetic energy of the photoelectrons depends only on ______
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 ______.
Find the energy of photon which have momentum 2 × 10-16 gm-cm/sec.
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.
When light falls on a metal surface, the maximum kinetic energy of the emitted photoelectrons depends upon ______
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) ____________.
The work function of a metal is 1.6 x 10-19 J. When the metal surface is illuminated by the light of wavelength 6400 Å, then the maximum kinetic energy of emitted photo-electrons will be (Planck's constant h = 6.4 x 10-34 Js) ____________.
The work function of a metallic surface is 5.01 eV. The photoelectrons are emitted when light of wavelength 2000 Å falls on it. The potential difference applied to stop the fastest photoelectrons is [h = 4.14 x 10-15 eV sec] ____________.
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A metal surface is illuminated by photons of energy 5 eV and 2.5 eV respectively. The ratio of their wavelengths is ____________.
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Which one of the following statements ts INCORRECT for stopping potential in photoelectric emission?
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When the work function of a metal increases, maximum kinetic energy of emitted photoelectrons ____________.
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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 ______.
On a photosensitive material when frequency of incident radiation is increased by 30%, kinetic energy of emitted photoelectrons increases from 0.4 eV. The work function of the surface is ______.
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 ______.
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 ______.
Define photoelectric work function of a metal.
