Lab 3: Electric Fields II
... Gravity, you remember, is not a force that acts when two objects touch. It is a force that seems to act over a distance. Physicists have never been happy with the idea of “action-at-a-distance.” Rather, they prefer to think about a gravitational field that is created by one object, like the sun. The ...
... Gravity, you remember, is not a force that acts when two objects touch. It is a force that seems to act over a distance. Physicists have never been happy with the idea of “action-at-a-distance.” Rather, they prefer to think about a gravitational field that is created by one object, like the sun. The ...
A Paradox Concerning the Energy of a Dipole in a Uniform External
... The integrand has the same value in any element dr d cos θ at a fixed angle θ independent of r. The contributions to the integral from such elements is independent of their distance r from charge. While the integral (7) is zero mathematically, we cannot say this is true in the physical universe with ...
... The integrand has the same value in any element dr d cos θ at a fixed angle θ independent of r. The contributions to the integral from such elements is independent of their distance r from charge. While the integral (7) is zero mathematically, we cannot say this is true in the physical universe with ...
L2 Gauss
... a vector p which points in the direction of the positive charge and has magnitude p = qd. What happens to the dipole in a constant field E? 1. Since the charges are equal and opposite, the force is zero. 2. The torque τ on the dipole is τ = p × E. 3. The potential energy of the dipole is U = –p·E. ...
... a vector p which points in the direction of the positive charge and has magnitude p = qd. What happens to the dipole in a constant field E? 1. Since the charges are equal and opposite, the force is zero. 2. The torque τ on the dipole is τ = p × E. 3. The potential energy of the dipole is U = –p·E. ...
Lecture 6: Maxwell`s Equations
... density Bx(z,t) near a planar vacuum-copper interface, assuming for copper: = 0 and = 5.8 x 107 S/m. Assume that a 60-Hz time-harmonic EM signal is ...
... density Bx(z,t) near a planar vacuum-copper interface, assuming for copper: = 0 and = 5.8 x 107 S/m. Assume that a 60-Hz time-harmonic EM signal is ...
1. ALTERNATING VOLTAGES AND CURRENT
... general, Ohm's law cannot be applied to alternating-current circuits since it does not consider the reactance which is always present in such circuits. However, by a modification of Ohm's law which does take into consideration the effect of reactance we obtain a general law which is applicable to ac ...
... general, Ohm's law cannot be applied to alternating-current circuits since it does not consider the reactance which is always present in such circuits. However, by a modification of Ohm's law which does take into consideration the effect of reactance we obtain a general law which is applicable to ac ...
Pdf - Text of NPTEL IIT Video Lectures
... And the magnetic fields are horizontally oriented and there again having the same amplitude all across, so this is the direction of the magnetic field. So, though direction is taken appropriately so that E cross H gives me the power flow which is in this direction. So, this is magnetic field which i ...
... And the magnetic fields are horizontally oriented and there again having the same amplitude all across, so this is the direction of the magnetic field. So, though direction is taken appropriately so that E cross H gives me the power flow which is in this direction. So, this is magnetic field which i ...
CH25 p670
... term electromotive force is misleading. Like many other historical terms still in use, it originated before the related principles—in this case, those of electricity—were well understood. The EMF is the influence that makes current flow from lower to higher potential, like a water pump in a water fo ...
... term electromotive force is misleading. Like many other historical terms still in use, it originated before the related principles—in this case, those of electricity—were well understood. The EMF is the influence that makes current flow from lower to higher potential, like a water pump in a water fo ...
Magnetic-field aligned electric fields in collisionless space plasmas
... (1) the ”mapping” of electric fields along magnetic field lines breaks down, and (2) plasma elements which are at one time in a common magnetic field line may be on different field lines at another time (Figure 2). This means for example that the electric field pattern, and the corresponding convect ...
... (1) the ”mapping” of electric fields along magnetic field lines breaks down, and (2) plasma elements which are at one time in a common magnetic field line may be on different field lines at another time (Figure 2). This means for example that the electric field pattern, and the corresponding convect ...
HIGH-ENERGY ASTROPHYSICS AND AXION
... According to the Tevcat catalog, 43 blazars with known redshift have been detected in the VHE so far, and 39 of them are in the flaring state, whose typical lifetime ranges from a few hours to a few days. We discard 1ES 0229+200 and 1ES 0347-121 from our discussion, since an analysis of their proper ...
... According to the Tevcat catalog, 43 blazars with known redshift have been detected in the VHE so far, and 39 of them are in the flaring state, whose typical lifetime ranges from a few hours to a few days. We discard 1ES 0229+200 and 1ES 0347-121 from our discussion, since an analysis of their proper ...
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.