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प्रश्न
Describe briefly how the Davisson-Germer experiment demonstrated the wave nature of electrons.
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उत्तर
Experiment:
Experimental arrangement used by Davisson and Germer: Electrons from a hot tungsten cathode are accelerated by a potential difference V between the cathode (C) and anode (A).
A narrow hole in the anode renders the electrons into a fine beam of electrons and allows them to strike a nickel crystal.
The electrons are scattered in all directions by the atoms in the crystal and its intensity in a given direction is found by the use of a detector.
The graph is plotted between angle Φ (angle between incident and the scattered direction of the electron beam) and intensity of the scattered beam.
The experimental curves obtained by Davisson and Germer are as shown in the figure below:
संबंधित प्रश्न
Calculate the momentum of the electrons accelerated through a potential difference of 56 V.
What is the de Broglie wavelength of a nitrogen molecule in air at 300 K? Assume that the molecule is moving with the root-mean square speed of molecules at this temperature. (Atomic mass of nitrogen = 14.0076 u)
The energy and momentum of an electron are related to the frequency and wavelength of the associated matter wave by the relations:
E = hv, p = `"h"/lambda`
But while the value of λ is physically significant, the value of v (and therefore, the value of the phase speed vλ) has no physical significance. Why?
The wavelength λ of a photon and the de-Broglie wavelength of an electron have the same value. Show that energy of a photon in (2λmc/h) times the kinetic energy of electron; where m, c and h have their usual meaning.
Sodium and copper have work function 2.3 eV and 4.5 eV respectively. Then, the ratio of the wavelengths is nearest to ______.
A proton, a neutron, an electron and an α-particle have same energy. Then their de Broglie wavelengths compare as ______.
The de Broglie wavelength of a photon is twice the de Broglie wavelength of an electron. The speed of the electron is `v_e = c/100`. Then ______.
- `E_e/E_p = 10^-4`
- `E_e/E_p = 10^-2`
- `p_e/(m_ec) = 10^-2`
- `p_e/(m_ec) = 10^-4`
An alpha particle is accelerated through a potential difference of 100 V. Calculate:
- The speed acquired by the alpha particle, and
- The de-Broglie wavelength is associated with it.
(Take mass of alpha particle = 6.4 × 10−27 kg)
How will the de-Broglie wavelength associated with an electron be affected when the velocity of the electron decreases? Justify your answer.
E, c and `v` represent the energy, velocity and frequency of a photon. Which of the following represents its wavelength?
