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AC GENERATION | cHaPtEr SiX
The machine that converts mechanical motion into electrical energy does so by spinning a magnet inside of a coil of wire. This spinning magnet causes the opposite poles to alternately pass near a conductor. The electrons will rst rush away from the negative pole of the magnet, creating a positive voltage. As the rotation continues, the electrons will rush back toward the positive pole of the magnet, creating a negative voltage. In AC circuits,
the terms positive and negative refer to the direction of current ow in a conductor. Although the coils are generally stationary and the magnet is spun, a spinning coil is shown for illustration purposes.
If the voltage causes electrons to ow away from the generating source, the voltage is positive. If the voltage causes electrons to ow toward the generating source, the voltage is negative. This is known as polarity.
+
factors are:
• The number of turns in the coil of wire
• The strength of the magnetic eld
• The speed at which the magnetic lines of ux pass through the coil
In order for a generator to produce one volt, a single conductor must pass through 100,000,000 lines of ux in one second. If the conductor is doubled and spun at the same rate, two volts would be produced. If we continue to coil the conductor, we will achieve a higher voltage even though the speed and strength of the magnetic eld remain constant.
In AC circuits, the terms positive and negative refer to the direction
of current ow in a conductor.
Positive Voltage + Negative Voltage The strength of the voltage to be produced depends on three factors. These
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