30 Questions
What is the speed range of the cathode ray particles as determined by Thomson's experiment?
0.1 to 0.2 times the speed of light
What did Thomson's observation about the value of e/m being independent of the cathode material or the gas suggest?
The universality of the cathode ray particles
In 1887, what was found about certain metals when irradiated by ultraviolet light?
They emitted negatively charged particles with small speeds
What did the observation about metals emitting negatively charged particles when heated to high temperatures establish?
The identical nature of these particles to cathode ray particles
What did J.J. Thomson name the negatively charged particles discovered through his experimental investigations?
Electrons
For his discovery of electrons and contributions to the conduction of electricity by gases, in which year was J.J. Thomson awarded the Nobel Prize in Physics?
1906
What does it mean when the text states that an electron's position uncertainty is infinite?
The electron is located in a finite region of space.
How does a wave packet differ from a wave with a fixed wavelength?
A wave packet extends over some finite region of space, while a fixed wavelength wave extends all over space.
According to de Broglie's relation, what happens to the momentum of an electron associated with a wave packet?
The momentum has an uncertainty and spreads out.
What property of a wave packet allows it to have an uncertainty in both position and momentum?
Extending over some finite region of space
How do the concepts of de Broglie relation, Born's probability interpretation, and wave packets relate to Heisenberg's uncertainty principle?
They form the basis for explaining Heisenberg's uncertainty principle.
How does the depiction of an electron as a localised wave packet differ from that of an extended wave with fixed wavelength?
The localised wave packet is spread over a finite region, while the extended wave is localized.
Who formulated the laws of refraction in 1621?
Snell
When did Huygens propose that light consists of waves?
Around 1650-60
Which model of light was merely a philosophical proposal without scientific experiments or arguments?
Descartes' particle theory
What did both Descartes and Newton's models of light manage to explain?
All the known properties of light
Which scientist extended Descartes' particle model and built it up as a scientific theory?
Newton
What was the speed of light concluded to be by scientists before accurate measurement was possible?
Higher than the limit of their measurement
What does |A|^2∆V represent in the context of matter waves?
Probability of the particle being found in a small volume around a point
In the context of matter waves, what does a large intensity indicate about the probability of finding a particle?
Greater probability of finding the particle
What is the formula for de Broglie wavelength of a moving particle?
$\lambda = \frac{h}{p}$
Given an electron moving three times as fast as another particle, what is the ratio of their de Broglie wavelengths?
$1.813 × 10^{-4}$
What determines the mass of a moving particle in the context of de Broglie wavelength?
$\frac{h}{\lambda v}$
When an electron is accelerated through a potential difference, what happens to its de Broglie wavelength?
Increases substantially
Who discovered double refraction of light in some crystals in 1669?
Bartholinus
What theory did Huygens use to explain the double refraction of light in crystals?
Wave theory
Which experiment performed in 1801 demonstrated interference fringes and supported the wave theory of light?
Young's double-slit experiment
What phenomenon, observed around 1810, could be naturally explained by the wave theory of light?
Polarisation
Why was Newton’s particle model of light preferred over the wave model for over a century?
Simplicity and contemporary physics influence
What value was determined for the speed of light in vacuum in the nineteenth century through accurate experiments?
$3 × 10^8$ m/s
This quiz covers the concepts related to de Broglie wavelength and particle velocity in quantum mechanics. It includes examples to calculate the de Broglie wavelength of particles with different velocities. Practice your understanding of wave-particle duality and probability in quantum mechanics.
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