FIGURE 63. WAVELENGTH MEASUREMENT.

i. *Alternating Current Values*. In discussing alternating

current and voltage, it is often necessary to express the

current and voltage in terms of MAXIMUM or PEAK values, PEAKto

PEAK values, EFFECTIVE values, AVERAGE values, or INSTANTANEOUS

values. Each of these values has a different meaning and is

used to describe a different amount of current or voltage.

(1) *PEAK And PEAKTOPEAK Values*. Refer to figure 64 on the

following page. Notice it shows the positive alternation of a

sine wave (a halfcycle of ac) and a dc waveform that occur

simultaneously. Note that the do starts and stops at the same

moment as does the positive alternation, and that both waveforms

rise to the same maximum value. However, the dc values are

greater than the corresponding ac values at all points except

the point at which the positive alternation passes through its

maximum value. At this point the dc and ac values are equal.

his point on he ine wave is referred to as the maximum o

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peak value.