JRE SCHOOL OF Engineering
... The presence of a magnetic field causes the critical temperature of type I super conductor to decrease as shown in fig. If the magnetic field exceeds a certain critical value Hc. which depends on material and its temperature it super conductivity disappears altogether. Such materials are super condu ...
... The presence of a magnetic field causes the critical temperature of type I super conductor to decrease as shown in fig. If the magnetic field exceeds a certain critical value Hc. which depends on material and its temperature it super conductivity disappears altogether. Such materials are super condu ...
Magnetic Force Exerted by a Magnetic Field on a Single
... are charged particles and the magnet is made of iron. Because all conductors attract electrically charged particles, the experiment above is not related to magnetism. How can you convince your friend that she is mistaken? Electrically charged particles exert forces that are either towards (attractiv ...
... are charged particles and the magnet is made of iron. Because all conductors attract electrically charged particles, the experiment above is not related to magnetism. How can you convince your friend that she is mistaken? Electrically charged particles exert forces that are either towards (attractiv ...
General Physics II
... rod, as indicted in the last step. Incidentally, we could have gotten here much more quickly with a little intuition. If we recognize that there must be a current flowing in the resistor due to the induced voltage caused by the motion of the rod, then we know there is power dissipated in the resisto ...
... rod, as indicted in the last step. Incidentally, we could have gotten here much more quickly with a little intuition. If we recognize that there must be a current flowing in the resistor due to the induced voltage caused by the motion of the rod, then we know there is power dissipated in the resisto ...
F = qvxB = qvBsinθ F
... b) Φ = BA cos θ = (1.22x 10−5T )(0.004m)2 cos 0 = 2.0x 10−10Wb c) Since the current is decreasing, Bw is decreasing, so the magnetic flux in the loop is decreasing. To oppose the change a current is induced in coil 2 that produces a B-field in the same direction as the Bw-field inside the loop d) Il ...
... b) Φ = BA cos θ = (1.22x 10−5T )(0.004m)2 cos 0 = 2.0x 10−10Wb c) Since the current is decreasing, Bw is decreasing, so the magnetic flux in the loop is decreasing. To oppose the change a current is induced in coil 2 that produces a B-field in the same direction as the Bw-field inside the loop d) Il ...
Magnetic Field
... Electric charges are source of electric fields. An electric field exerts force on an electric charge, whether the charge happens to be moving or at rest. One could similarly think of a magnetic charge as being the source of a magnetic field. However, isolated magnetic charge ( or magnetic monopoles) ...
... Electric charges are source of electric fields. An electric field exerts force on an electric charge, whether the charge happens to be moving or at rest. One could similarly think of a magnetic charge as being the source of a magnetic field. However, isolated magnetic charge ( or magnetic monopoles) ...
... 1.An electron beam passes through a region of crossed electric and magnetic fields of strengths E and B respectively. For what value of electron speed the beam will remain undeflected? 2.As soon as the current is switched on ahigh voltage wire, the bird sitting on it flies away, why? 3.A semiconduct ...
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.