On the interaction of electromagnetic waves with conductors
... Thus we see, in a very simple and pedagogical manner, that at radio frequencies an electromagnetic wave will travel a great distance along the surface of the earth due to multiple reflections off the ionosphere. Here the free electron model is sufficient to explain this behaviour. On the other hand, ...
... Thus we see, in a very simple and pedagogical manner, that at radio frequencies an electromagnetic wave will travel a great distance along the surface of the earth due to multiple reflections off the ionosphere. Here the free electron model is sufficient to explain this behaviour. On the other hand, ...
A3295 - Allegro Microsystems
... The Hall element can be considered as a resistor array similar to a Wheatstone bridge. A basic circuit is shown in figure 1, demonstrating the effect of the magnetic field flux density, B, impinging on the Hall element. When using Hall effect technology, a limiting factor for switchpoint accuracy is ...
... The Hall element can be considered as a resistor array similar to a Wheatstone bridge. A basic circuit is shown in figure 1, demonstrating the effect of the magnetic field flux density, B, impinging on the Hall element. When using Hall effect technology, a limiting factor for switchpoint accuracy is ...
2.1 Ohm's Law and Theory of Charge Transport
... Note also that electrical current flow without an electrical field as primary driving force as outlined above is not some odd special case, but at the root of most electronic devices that are more sophisticated than a simple resistor. Of course, if you have different particles, with different densit ...
... Note also that electrical current flow without an electrical field as primary driving force as outlined above is not some odd special case, but at the root of most electronic devices that are more sophisticated than a simple resistor. Of course, if you have different particles, with different densit ...
Curie-Weiss law in thin-film ferroelectrics
... be totally suppressed, when the film thickness is below certain critical values. This dependence of the phase-transition characteristics on the sample size has been investigated using both first-principles calculations1,2 and thermodynamic models.3–5 Experiments have also confirmed that the Curie te ...
... be totally suppressed, when the film thickness is below certain critical values. This dependence of the phase-transition characteristics on the sample size has been investigated using both first-principles calculations1,2 and thermodynamic models.3–5 Experiments have also confirmed that the Curie te ...
Mapping Electric Fields
... The potential difference, V, between points A and B is defined by: WAB VAB = - q where WAB is the work required to move the charge q from point A to point B. Therefore potential is always measured between two points. Since only the difference matters you can choose any convenient reference point to ...
... The potential difference, V, between points A and B is defined by: WAB VAB = - q where WAB is the work required to move the charge q from point A to point B. Therefore potential is always measured between two points. Since only the difference matters you can choose any convenient reference point to ...
jan22
... we were to place something in the field (as was done in the animation above) and watch it move it would move outward without any rotation. ...
... we were to place something in the field (as was done in the animation above) and watch it move it would move outward without any rotation. ...
Anisotropy and Magnetization Reversal
... How is µL coupled to the lattice ? If the local crystal field seen by an atom is of low symmetry and if the bonding electrons of that atom have an asymmetric charge distribution (Lz ≠ 0), then the atomic orbits interact anisotropically with the crystal field. In other words, certain orientation for ...
... How is µL coupled to the lattice ? If the local crystal field seen by an atom is of low symmetry and if the bonding electrons of that atom have an asymmetric charge distribution (Lz ≠ 0), then the atomic orbits interact anisotropically with the crystal field. In other words, certain orientation for ...
The discovery of superconductivity
... the historic entry, “practically zero.” The notebook further records that the helium level stood quite still. The experiment continued into the late afternoon. At the end of the day, Kamerlingh Onnes finished with an intriguing notebook entry: “Dorsman [who had controlled and measured the temperatur ...
... the historic entry, “practically zero.” The notebook further records that the helium level stood quite still. The experiment continued into the late afternoon. At the end of the day, Kamerlingh Onnes finished with an intriguing notebook entry: “Dorsman [who had controlled and measured the temperatur ...
Document
... In the 5th semester you will revisit conduction in solids and find that many of the equations we developed in the Drude model are actually OK – The biggest problem is Drude´s interpretation of – the scattering time A quantum mechanical treatment of an electron moving in a periodic Coulomb potent ...
... In the 5th semester you will revisit conduction in solids and find that many of the equations we developed in the Drude model are actually OK – The biggest problem is Drude´s interpretation of – the scattering time A quantum mechanical treatment of an electron moving in a periodic Coulomb potent ...
Superconductivity
Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic fields occurring in certain materials when cooled below a characteristic critical temperature. It was discovered by Dutch physicist Heike Kamerlingh Onnes on April 8, 1911 in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum mechanical phenomenon. It is characterized by the Meissner effect, the complete ejection of magnetic field lines from the interior of the superconductor as it transitions into the superconducting state. The occurrence of the Meissner effect indicates that superconductivity cannot be understood simply as the idealization of perfect conductivity in classical physics.The electrical resistivity of a metallic conductor decreases gradually as temperature is lowered. In ordinary conductors, such as copper or silver, this decrease is limited by impurities and other defects. Even near absolute zero, a real sample of a normal conductor shows some resistance. In a superconductor, the resistance drops abruptly to zero when the material is cooled below its critical temperature. An electric current flowing through a loop of superconducting wire can persist indefinitely with no power source.In 1986, it was discovered that some cuprate-perovskite ceramic materials have a critical temperature above 90 K (−183 °C). Such a high transition temperature is theoretically impossible for a conventional superconductor, leading the materials to be termed high-temperature superconductors. Liquid nitrogen boils at 77 K, and superconduction at higher temperatures than this facilitates many experiments and applications that are less practical at lower temperatures.