What is the characteristic feature of the peak of a sine wave?

The peak of a sine wave is defined as the point where the wave reaches its maximum voltage. In the context of an AC signal represented by a sine wave, this maximum voltage is critical as it indicates the highest level of voltage in the cycle of the waveform. Sine waves oscillate between a maximum and a minimum value, with the peak corresponding directly to the highest amplitude.

Understanding the peak voltage is essential in applications such as designing electrical circuits, selecting components (like capacitors and transformers), and ensuring that devices can handle the maximum voltage without risk of damage. Each wave cycle is symmetrical, and the peak is a significant point used in calculations involving root mean square (RMS) values, which are often used to express AC voltages.

The other options refer to different aspects of voltage in waveforms, like minimum levels, average levels, or DC offsets, but none of these represent the highest point of the sine wave, which is why they are not the correct answer. The characteristic feature of the sine wave's peak remains the maximum voltage, emphasizing the amplitude of the waveform.