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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 de Broglie wavelength of the electrons accelerated through a potential difference of 56 V.
The wavelength of light from the spectral emission line of sodium is 589 nm. Find the kinetic energy at which
(a) an electron, and
(b) a neutron, would have the same de Broglie wavelength.
Find the de Broglie wavelength of a neutron, in thermal equilibrium with matter, having an average kinetic energy of `(3/2)` kT at 300 K.
Obtain the de Broglie wavelength of a neutron of kinetic energy 150 eV. As you have an electron beam of this energy is suitable for crystal diffraction experiments. Would a neutron beam of the same energy be equally suitable? Explain. (mn= 1.675 × 10−27 kg)
When a light wave travels from air to glass ______.
An electromagnetic wave of wavelength ‘λ’ is incident on a photosensitive surface of negligible work function. If ‘m’ mass is of photoelectron emitted from the surface has de-Broglie wavelength λd, then ______
A particle moves in a closed orbit around the origin, due to a force which is directed towards the origin. The de Broglie wavelength of the particle varies cyclically between two values λ1, λ2 with λ1 > λ2. Which of the following statement are true?
- The particle could be moving in a circular orbit with origin as centre.
- The particle could be moving in an elliptic orbit with origin as its focus.
- When the de Broglie wavelength is λ1, the particle is nearer the origin than when its value is λ2.
- When the de Broglie wavelength is λ2, the particle is nearer the origin than when its value is λ1.
An electron is accelerated from rest through a potential difference of 100 V. Find:
- the wavelength associated with
- the momentum and
- the velocity required by the electron.
The equation λ = `1.227/"x"` nm can be used to find the de Brogli wavelength of an electron. In this equation x stands for:
Where,
m = mass of electron
P = momentum of electron
K = Kinetic energy of electron
V = Accelerating potential in volts for electron
Matter waves are ______.
