# what is form factor? crest factor? peak factor? & power factor? in ac circuits

## Form factor

Form factor is defined as the ratio of RMS value to the Average value. It is denoted as Kf

### (a) In terms of a.c. current

form factor for sinusoidal waveform is 1.11. It has no unit.

## Crest factor or Amplitude factor

Amplitude factor is defined as the ratio of maximum value to RMS value. It is denoted as Ka

therefore, Crest factor or Amplitude factor,

### (b) In terms of a.c. voltage

Crest factor for sinusoidal waveform is 1.414, It has no unit.

## Peak factor

It is defined as the ratio of maximum value to the RMS value of an alternating quantity.

## Power factor

The power factor is defined as the cosine of the angle between voltage and current in an circuit.

## Instantaneous value related to A.C. circuit

The value of an alternating quantity, i.e. voltage or current at any instant, is called its instantaneous value and is represented by ‘e’ or ‘i’ respectively.

here, are instantaneous value of current at time t1, t2 and t3.