Electrical Engineering ⇒ Topic : Peak or Amplitude or Crest Factor

Peak factor. The ratio of maximum value to the rm.s. value of an alternating quantity is known as peak factor i.e.

The value of peak factor also depends upon the waveform of the alternating quantity. For an alternating voltage or current varying sinusoidally, its value is 1.414 i.e.

For a sinusoidal voltage or current

The peak factor is of much greater importance because it indicates the maximum voltage being applied to the various parts of the apparatus. For instance, when an alternating voltage is applied across a cable or capacitor, the breakdown of insulation will depend upon the maximum voltage. The insulation must be able to withstand the maximum rather than the r. m.s. value of voltage.

Note. Peak factor is also called crest factor or amplitude factor.