The Amplitude of an AC waveform is the magnitude of the AC waveform at any particular instant. The magnitude of the Alternating current or voltage varies with the sine of the angle made by the circular movement of the magnet or coil with respect to the zero point.

The first characteristic of AC power is its "amplitude". Amplitude is the maximum value of current or voltage. It is represented by either of the two peaks of the since wave. This voltage level is also referred to as the peak voltage, and can be either positive or negative.

One of the key properties of an AC waveform, asides frequency and period, is the Amplitude which represents the maximum value of an alternating waveform or as better known, the peak value.

The basic characteristics of an AC waveform are as follows: Amplitude Frequency Period Amplitude The peak value or the maximum value that a waveform achieves is called its amplitude. This length is measured from the x-axis, i.e., the zero line.