**Form factor** is defined as the ratio of RMS value to the average value of a waveform. The waveform can be quantity like voltage, current, etc. This parameter is generally used in the rectifiers.

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## Form factor Formula

where,

A_{rms} is the rms value of the waveform

A_{avg} is the average value of the waveform

### Form factor of Half wave rectifier

The RMS value of output current of single-phase half-wave rectifier is given by

where, I_{m} is the peak value of output current.

The average value of output current of single-phase half-wave rectifier is given by

where, I_{m} is the peak value of output current.

As we know that form factor is given by

Therefore, we get

∴ Form factor = π/2 = 1.5707963

The form factor of half wave rectifier is 1.5707963

### Form factor of Full wave rectifier

The RMS value of output current of single-phase full-wave rectifier is given by

where, I_{m} is the peak value of output current.

The average value of output current of single-phase full-wave rectifier is given by

where, I_{m} is the peak value of output current.

As we know that form factor is given by

Therefore, we get

∴ Form factor = 1.11072073

The form factor of full wave rectifier is 1.11072073

### Form factor of Bridge rectifier

The RMS value of output current of Bridge rectifier is given by

where, I_{m} is the peak value of output current.

The average value of output current of Bridge rectifier is given by

where, I_{m} is the peak value of output current.

As we know that form factor is given by

Therefore, we get

∴ Form factor = 1.11072073

The form factor of bridge rectifier is 1.11072073