Figure 1-17. - Effects between magnetic poles.

Figure 1-18. - Electromagnetism.

curve of the wire. If two loops are made in the conductor, the lines of force will circle the two loops. In the area between the adjacent loops, the magnetic lines are going in opposite directions. In such a case, because they are of the same strength (from same amount of current traveling in both loops), they cancel each other out. The lines of force, therefore, circle the two loops almost as though they were a single loop. However, the magnetic field will be twice as strong because the lines of force of the two loops combine.

When many loops of wire are formed into a coil, as shown in figure 1-20, the lines of force of all loops combine into a pattern that greatly resembles the magnetic field surrounding a bar magnet. A coil of this

Figure 1-19. - Electromagnetism in a wire loop.

Figure 1-20. - Electromagnetism in a wire coil.