Quiz 9.1, 9.2 Study Guide
... As temperature increases, resistance increases. As diameter increases, resistance decreases. As length increases, resistance increases. Conductors have less resistance than insulators. Ex: If two wires of the same material have the same thickness but different lengths, the shorter wire will have les ...
... As temperature increases, resistance increases. As diameter increases, resistance decreases. As length increases, resistance increases. Conductors have less resistance than insulators. Ex: If two wires of the same material have the same thickness but different lengths, the shorter wire will have les ...
![superconductive magnetic storage [AF/Hilal proposal] - tii](http://s1.studyres.com/store/data/009158032_1-b96dcba36080aa7c88acc28ac5595d75-300x300.png)
对流(运流)电流(DK Cheng, p. 198)
... Convection current, the result of hydrodynamic motion involving a mass transport, are not governed by Ohm’s law. (D. K. Cheng, p. 199) When an external electric field is applied on a conductor, an organized motion of the conduction electrons will result, producing an electric current. The average dr ...
... Convection current, the result of hydrodynamic motion involving a mass transport, are not governed by Ohm’s law. (D. K. Cheng, p. 199) When an external electric field is applied on a conductor, an organized motion of the conduction electrons will result, producing an electric current. The average dr ...
chp30
... - Capacitor stores energy in the electric field between its plates L-C Circuit - An LC circuit creates oscillating current and charge - Energy is transferred between the capacitors magnetic field, into the inductors magnetic field, and back. - The derived equation for a capacitor and inductor in ser ...
... - Capacitor stores energy in the electric field between its plates L-C Circuit - An LC circuit creates oscillating current and charge - Energy is transferred between the capacitors magnetic field, into the inductors magnetic field, and back. - The derived equation for a capacitor and inductor in ser ...
ISC-Physics-Sample-p..
... a) Using Ampere’s Circuital Law and with the help of a labelled diagram, show that magnetic flux density ‘B’ at a distance r from a long straight conductor is given by : B = μoI/2 r, where the terms have their usual meaning. ...
... a) Using Ampere’s Circuital Law and with the help of a labelled diagram, show that magnetic flux density ‘B’ at a distance r from a long straight conductor is given by : B = μoI/2 r, where the terms have their usual meaning. ...
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.