When an AC voltage has an amplitude of zero (0), it means that the voltage is not oscillating or varying around a mean value. In other words, the voltage is constant and does not change over time.
In alternating current (AC), the voltage continuously changes its magnitude and polarity, oscillating between positive and negative values. The amplitude of an AC voltage refers to the maximum value that the voltage reaches during each cycle.
If the amplitude of an AC voltage is zero, it implies that the voltage remains at a constant value of zero volts. This indicates that there is no voltage difference or potential between the two points in the circuit. In practical terms, it suggests that there is no electrical energy being transferred or no electrical signal present.
It's important to note that a zero amplitude does not necessarily mean that there is no voltage in the circuit. There could be other AC components or signals present that have non-zero amplitudes, but the specific component being referred to has an amplitude of zero.