Basic Electrical Installation Work

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10.12. Definition A mutual inductance henry exists between two coils when uniformly varying current ampere per sec- ond one coil produces emf 1 volt the other coil. 10. Suitable materials will, there- fore, display narrow hysteresis loop, shown loop (a) Fig.12 Magnetic hysteresis loops: (a) electromagnetic material and (b) permanent magnetic material. . B H (a) B H (b) Magnetic saturation Definition Magnetic hysteresis loops describe the way which different materials respond being magnetized. Some materials magnetize easily, and some are difficult magnetize. When iron core subjected alternating magnetization, trans- former, the energy loss occurs every cycle and constitutes continu- ous power loss, and, therefore, for applications such transformers, a material with narrow hysteresis loop required.11 dependent upon the rate change magnetic flux and the num- ber turns the coil. The arc produced the stored magnetic energy being discharged across the switch contacts.12 and are called hysteresis loops. The core electromagnet required magnetize easily, and lose its magnetism equally easily when switched off. Magnetic hysteresis There are many different types magnetic material and they all respond differently being magnetized. A mutual inductance henry exists between two coils when uniformly varying current ampere per second one coil produces emf volt in the other coil. The result will look like the graphs shown Fig. The emf induced coil such that shown the right-hand side Fig. Magnetic hysteresis loops describe the way which different materials respond being magnetized.Baisc Electrical Installation Work 206 FIGURE 10. 10. Materials from which permanent magnets are made should display wide hysteresis loop, shown loop (b) Fig. Some materials retain their magnetism, while others lose it. Energy stored magnetic field When open the switch inductive circuit such electric motor or fluorescent light circuit the magnetic flux collapses and produces an arc across the switch contacts. 10.12