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Bohr's Postulates

The French ph...

Question

The French physicist, de Broglie, in 1924 proposed that matter, like radiation, should also ? exhibit dual behaviour i.e., both particle and wavelike properties. This means that just as the photon has momentum as well as wavelength, electrons should also have momentum as well ? as wavelength. De Broglie gave a relation between wavelength and momentum ?
Q1.What is de Broglie?s relation? ?
Q2.Why are de Broglie?s wavelength associated with a moving football is not visible?

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Solution

Dear student,

Ans-1 The de Broglie equation is:
λ = h/mv
where,
λ is wavelength, h is Planck's constant, m is the mass of a particle, moving at a velocity v.
p(momentum) = mv
λ = h/p

Ans-2 De Broglie's wavelength is not visible with a moving football because of its large mass , the wavelength associated is very small. So, its wave nature is not visible.

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The French physicist Louis de Broglie in 1924 postulated that matter, like radiation, should exhibit a dual behavior. He proposed the following relationship between the wavelength

λ

of a material particle, its linear momentum p and Planck constant h.

λ = \frac{h}{p} = \frac{h}{m v}

The de Broglie relation implies that the wavelength of a particle should decrease as its velocity increases. It also implies that for a given velocity heavier particles should have a shorter wavelength than lighter particles. The waves associated with particles in motion are called matter waves or de-Broglie waves. These waves differ from the electromagnetic wave as they
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The experimental confirmation of the de Broglie relation was obtained when Davisson and Germer, in 1927, observed that a beam of electrons is diffracted by a nickel crystal. As diffraction is a characteristic property of waves, hence the beam of electron behaves as a wave, as proposed by de Broglie.

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Q. The French physicist Louis de Broglie in 1924 postulated that matter, like radiation, should exhibit a dual behaviour. He proposed the following relationship between the wavelength lambda of a material particle, its linear momentum p and planck constant h.

λ = \frac{h}{p} = \frac{h}{m v}

The de Broglie relation implies that the wavelength of a particle should decrease as its velocity increases. It also implies that for a given velocity heavier particles should have shorter wavelength than lighter particles. The waves associated with particles in motion are called matter waves or de Broglie waves. These waves differ from the electromagnetic waves as they

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have lower velocities

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have no electrical and magnetic fields and

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are not emitted by the particle under consideration.
The experimental confirmation of the de Broglie’s relation was obtained when Davisson and Germer, in 1927, observed that a beam of electrons is diffracted by a nickel crystal. As diffraction is a characteristic property of waves, hence the beam of electron behaves as a wave, as proposed by de Broglie.

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The French physicist Louis de Broglie in 1924 postulated that matter, like radiation, should exhibit a dual behaviour. He proposed the following relationship between the wavelengh

λ

of a material particle, its linear momentum p and planck constant h.

λ = \frac{h}{p} = \frac{h}{m v}

The de Broglie relation implies that the wavelength of a particle should decrease as its velocity increases. It also implies that for a given velocity heavier particles should have shorter wavelength than lighter particles. The waves differ from the electromagnetic waves as they
(i) have lower velocities
(ii) have no electrical and magnetic fields and
(iii) are not emitted by the particle under consideration.
The experimental confirmation of the de Broglie relation was obtained when Davisson and Germer, in 1927, observed that a beam of electrons is diffron behaves as a wave, as proposed by de Broglie. Wemer Heisenberg considered the limits of how precisely we can measure properties of an electron or other microscopic particle like electron. He determined that there is a fundametal limit of how closely we can measure both position and mometum. The more accurately we measure the mokmentum of a particle, the less accurately we can determine its position. The converse is also true. This is summed up in what we now call the "Heisenberg uncertainty principle; It is impossible to determine simultanously and precisely both the momentum and position of a particle. The product of uncertainty in the position,

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