In this chapter, we will examine an important kind of passive component called inductor, also known as solenoid, coil, or choke.
10.2 The Inductor
It is known that a current flowing in a wire creates a magnetic field, but what happens to the magnetic field when the wire is wounded to a coil, like the one shown in Figure 10.1? Is the field the same as if the wire was straight?
No, the field is not the same. The winding creates a single longitudinal magnetic field that is the combination of all magnetic fields of the coil sections.
In Figure 10.2, the arrow shows the magnetic field created by a coil for a current that enters by the base.
Figure 10.2 Magnetic field generated by a coil for the current entering its base.
The magnetic field generated by a coil is basically located inside the coil.
Magnetic fields are measured in Tesla and represented by the uppercase letter T in the SI.
Figure 10.3 shows a transversal section of an inductor like the one shown in Figure 10.2 and its respective magnetic field lines. Figure 10.3 also shows how each of the individual magnetic field lines combines to generate a stronger longitudinal magnetic field (B).
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