Magnetic Field and Polarity of a Coil

MAGNETISM Basic Electrical Theory Magnetic Field and Polarity of a Coil Bending a straight conductor into a loop has two results: (1) magnetic field lines become more dense inside the loop, and (2) all lines inside the loop are aiding in the same direction. When a conductor is shaped into several loops, it is considered to be a coil. To determine the polarity of a coil, use the left-hand rule for coils (Figure 23). Figure 23 Left-hand Rule for Coils Adding an iron core inside of a coil will increase the flux density. The polarity of the iron core will be the same as that of the coil. Current flow is from the negative side of the voltage source, through the coil, and back to the positive side of the source (Figure 24). ES-01 Page 32 Rev. 0