Document
... created by that current has a magnetic flux through the area of the loop. If the current changes, the magnetic field changes, and so the flux changes giving rise to an induced emf. This phenomenon is called self-induction because it is the loop's own current, and not an external one, that gives rise ...
... created by that current has a magnetic flux through the area of the loop. If the current changes, the magnetic field changes, and so the flux changes giving rise to an induced emf. This phenomenon is called self-induction because it is the loop's own current, and not an external one, that gives rise ...
Electromechanical Simulation Of A Linear Solenoid Actuator
... upon the armature was measured on the real actuator. This force can be calculated for the simulated model using the principle of Maxwell’s tensor. The calculated force matches very well with reality. Dynamic characteristics of the actuator were measured by applying a quadratic voltage pulse to the c ...
... upon the armature was measured on the real actuator. This force can be calculated for the simulated model using the principle of Maxwell’s tensor. The calculated force matches very well with reality. Dynamic characteristics of the actuator were measured by applying a quadratic voltage pulse to the c ...
CURRENT, RESISTANCE, AND ELECTROMOTIVE FORCE
... ratio of the magnitudes of electric field and current density. • Good conductors have small resistivity; good insulators have large resistivity. ...
... ratio of the magnitudes of electric field and current density. • Good conductors have small resistivity; good insulators have large resistivity. ...
Magnetic plasmon modes in periodic chains of nanosandwiches S.M. Wang , T. Li
... field in y=0 plane are plotted in Fig. 2(a) and 2(b) at 2.7 × 10 14 Hz. It is shown that the magnetic resonances excited in the nanosandwiches with the direction perpendicular to the chain, which forms the magnetic plasmon in the chain. To show the sub-wavelength property, we also investigate the po ...
... field in y=0 plane are plotted in Fig. 2(a) and 2(b) at 2.7 × 10 14 Hz. It is shown that the magnetic resonances excited in the nanosandwiches with the direction perpendicular to the chain, which forms the magnetic plasmon in the chain. To show the sub-wavelength property, we also investigate the po ...
Document
... perpendicular to both the field and the charges movement, and whats to say the force is one way instead of the other? seems really arbitrary compared to gravity or coulomb's law Magnetic fields are caused by charges in motion or current, right? How does current flow in something like a bar magnet? W ...
... perpendicular to both the field and the charges movement, and whats to say the force is one way instead of the other? seems really arbitrary compared to gravity or coulomb's law Magnetic fields are caused by charges in motion or current, right? How does current flow in something like a bar magnet? W ...
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.