b. You also saw in a previous lesson what happens to a conductor when
it is placed between the poles of a permanent magnet. The conductor moves
because of the interaction between the two magnetic fields. Figure 89 shows
you why the conductor moves.
c. The field of the magnet adds to the conductor magnetic field on one
side and cancels the conductor magnetic field on the other side.
The
combination of a weak field above the conductor and a strong field below the
conductor makes the conductor move up. In other words, the stronger field
below pushes the conductor into the weaker field above the conductor.
Figure 89. How a Current-Carrying Conductor
Moves in a Magnetic Field.
13. A permanent magnet can also move electrons in a diode.
a. Notice the cartoonized version of diode action shown in Part A of
Figure 90. It shows how electrons emitted from the hot cathode go directly
to the anode when the anode is positive with respect to the cathode.
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