Ward identity and Thermo-electric conductivities
... Thus the field theory system has metric, external gauge field and scalars(axions) as sources. We can apply the Ward identity to this system. ...
... Thus the field theory system has metric, external gauge field and scalars(axions) as sources. We can apply the Ward identity to this system. ...
Document
... Twice the speed of Amtrak’s fastest conventional train! May eventually use superconducting loops to produce B-field ...
... Twice the speed of Amtrak’s fastest conventional train! May eventually use superconducting loops to produce B-field ...
Physics 121 Lecture Summary
... o think of electric field lines “flowing” through the surface of area A o SI unit: N m2/C o if surface A is closed (like a sphere - a rectangle would be open) flux is positive if E field lines are leaving the enclosed surface flux is negative if E field lines are entering the enclosed surface o ...
... o think of electric field lines “flowing” through the surface of area A o SI unit: N m2/C o if surface A is closed (like a sphere - a rectangle would be open) flux is positive if E field lines are leaving the enclosed surface flux is negative if E field lines are entering the enclosed surface o ...
Magnetic Current Imaging Revisited
... 3 µm, and capability to differentiate dice in a stacked configuration have been demonstrated.[15] This innovation suggests MCI can be extended into a true, noninvasive 3-D fault-isolation technique. ...
... 3 µm, and capability to differentiate dice in a stacked configuration have been demonstrated.[15] This innovation suggests MCI can be extended into a true, noninvasive 3-D fault-isolation technique. ...
Document
... and toroidal fields. Velocity shear (differential rotation) naturally generates toroidal from poloidal field. The α-effect of mean field electrodynamics can complete the cycle and regenerate poloidal from toroidal field. With a judicial choice of α and β (and differential rotation ω) it is possible ...
... and toroidal fields. Velocity shear (differential rotation) naturally generates toroidal from poloidal field. The α-effect of mean field electrodynamics can complete the cycle and regenerate poloidal from toroidal field. With a judicial choice of α and β (and differential rotation ω) it is possible ...
Comparing DC Motors, Generators and Alternators
... a. Which choice (A-I in the answer key) best indicates the direction of the magnetic force on the wire at point x? b. Which choice (A-I in the answer key) best indicates the direction of the magnetic force on the wire at point y? c. Which choice (A-I in the answer key) best indicates the direction o ...
... a. Which choice (A-I in the answer key) best indicates the direction of the magnetic force on the wire at point x? b. Which choice (A-I in the answer key) best indicates the direction of the magnetic force on the wire at point y? c. Which choice (A-I in the answer key) best indicates the direction o ...
Magnetic Field in a Slinky
... magnetic field is present inside the solenoid. Solenoids are used in electronic circuits or as electromagnets. In this lab we will explore factors that affect the magnetic field inside the solenoid and study how the field varies in different parts of the solenoid. By inserting a Magnetic Field Senso ...
... magnetic field is present inside the solenoid. Solenoids are used in electronic circuits or as electromagnets. In this lab we will explore factors that affect the magnetic field inside the solenoid and study how the field varies in different parts of the solenoid. By inserting a Magnetic Field Senso ...
Current and Resistance
... Semiconductors are materials that have few conduction electrons but can become conductors when they are doped with other atoms that contribute charge carriers. In a semiconductor, n (number of free electrons) is small (unlike conductor) but increases very rapidly with temperature as the increased th ...
... Semiconductors are materials that have few conduction electrons but can become conductors when they are doped with other atoms that contribute charge carriers. In a semiconductor, n (number of free electrons) is small (unlike conductor) but increases very rapidly with temperature as the increased th ...
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.