TC 9-64 _________________________________________________________________________
magnetic force can be detected and measured. There are two other fields
involved--an induction field, which exists close to the conductor carrying the
current, and the radiation field, which becomes detached from the current-
carrying rod and travels through space.
1-128. To represent the magnetic field, lines of force are again used to
illustrate the energy. Magnetic lines are not drawn between the rods, nor
between high- and low-potential points, as the E lines that were discussed
earlier. The flow of current rather than the force of voltage creates magnetic
lines. The magnetic lines of force, therefore, are drawn at right angles to the
direction of current flow.
1-129. The magnetic fields that are set up around two parallel rods, as
shown in figure 1-28 view A, are in maximum opposition. Rod 1 contains a
current flowing from the generator, while rod 2 contains a current flowing
toward the generator. As a result, the direction of the magnetic field
surrounding rod 1 is opposite the direction of the magnetic field surrounding
rod 2. This will cause cancellation of part or all of both magnetic fields with a
resultant decrease in radiation of the electromagnetic energy. View B
illustrates that if the far ends of rods 1 and 2 are separated from each other
while the rods are still connected to the generator at the near ends, more
space--and consequently less opposition--will occur between the magnetic
fields of the two rods. View C illustrates that placing the rods in line makes
the currents through both rods flow in the same direction. Therefore, the two
magnetic fields are in the same direction; thus, maximum electromagnetic
radiation into space can be obtained.
Figure 1-28. Magnetic Fields around Elements
1-130. Magnetic lines of force are indicated by the letter H and are called H
lines. The direction of the magnetic lines may be determined by use of the
left-hand rule for a conductor: If you grasp the conductor in your left hand
1-38
Previous Page
