Sample Test Questions
... 4. [1] A wire made of a pure substance has length L, cross-sectional area A. The wire is now pulled so that it is thinner and its length is 1.5L. Is the resistance of the wire increased or decreased? ______ By what factor is the resistance changed? __________ Show work for credit. ...
... 4. [1] A wire made of a pure substance has length L, cross-sectional area A. The wire is now pulled so that it is thinner and its length is 1.5L. Is the resistance of the wire increased or decreased? ______ By what factor is the resistance changed? __________ Show work for credit. ...
If a bar magnet is divided into two equal pieces,
... A) increases steadily as we go to heavier elements. B) decreases steadily as we go to heavier elements. C) is approximately constant throughout the periodic table, except for very light nuclei. D) has a maximum near iron in the periodic table. E) is a periodic function ...
... A) increases steadily as we go to heavier elements. B) decreases steadily as we go to heavier elements. C) is approximately constant throughout the periodic table, except for very light nuclei. D) has a maximum near iron in the periodic table. E) is a periodic function ...
Magnetism - University of Colorado Boulder
... Cross-Product Review: The cross-product of two vectors is a third vector A B C defined like this: The magnitude of A B is A B sin . The direction of A B is the direction perpendicular to the plane defined by the vectors A and B plus right-hand-rule. (Curl fingers from first vector A to seco ...
... Cross-Product Review: The cross-product of two vectors is a third vector A B C defined like this: The magnitude of A B is A B sin . The direction of A B is the direction perpendicular to the plane defined by the vectors A and B plus right-hand-rule. (Curl fingers from first vector A to seco ...
AP Physics Test – Magnetism and EM Induction Name: Each of the
... 22) A particle with unknown mass and charge moves with constant speed v = 1.9 106 m/s as it passes undeflected through a pair of parallel plates, as shown above. The plates are separated by a distance d = 6.0 10-3 m, and a constant potential difference V is maintained between them. A uniform ma ...
... 22) A particle with unknown mass and charge moves with constant speed v = 1.9 106 m/s as it passes undeflected through a pair of parallel plates, as shown above. The plates are separated by a distance d = 6.0 10-3 m, and a constant potential difference V is maintained between them. A uniform ma ...
1 Current 2 Resistance and Ohm`s Law
... approximately by RT = R0 [1 + α (T − T0 )] where α is the temperature coefficient of resistivity . ...
... approximately by RT = R0 [1 + α (T − T0 )] where α is the temperature coefficient of resistivity . ...
Electric Motors
... opposites attract and like poles repel. So if you try to put two magnets together, south pole to south pole or north pole to north pole, they will push away from or repel one another. If you try to put a north pole close to the south pole of another magnet, the magnets will attract or move towards o ...
... opposites attract and like poles repel. So if you try to put two magnets together, south pole to south pole or north pole to north pole, they will push away from or repel one another. If you try to put a north pole close to the south pole of another magnet, the magnets will attract or move towards o ...
Self-Inductance RL Circuits Energy in a Magnetic Field Mutual
... When I changes, an emf is induced in the coil. If I is increasing (and therefore increasing the flux through the coil), then the induced emf will set up a magnetic field to oppose the increase in the magnetic flux in the direction shown. If I is decreasing, then the induced emf will set up a magnet ...
... When I changes, an emf is induced in the coil. If I is increasing (and therefore increasing the flux through the coil), then the induced emf will set up a magnetic field to oppose the increase in the magnetic flux in the direction shown. If I is decreasing, then the induced emf will set up a magnet ...
22 Electromagnetic Induction
... inducing a voltage in a conductor by changing the magnetic field around the conductor induced current the current produced by electromagnetic induction induced emf the voltage produced by electromagnetic induction Faraday’s law of induction law which states that a voltage can be induced in a conduct ...
... inducing a voltage in a conductor by changing the magnetic field around the conductor induced current the current produced by electromagnetic induction induced emf the voltage produced by electromagnetic induction Faraday’s law of induction law which states that a voltage can be induced in a conduct ...
Assignment for the Course `Ferroelectric materials and Applications`
... - Define in your own word the Saturation polarization Ps, the remnant polarization Pr, and the coercive field Ec. - What is the difference between Ps and Pr? Could they be the same? If yes, in which case? ...
... - Define in your own word the Saturation polarization Ps, the remnant polarization Pr, and the coercive field Ec. - What is the difference between Ps and Pr? Could they be the same? If yes, in which case? ...
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.