Generally, most people are familiar with alternating current (AC) in their everyday lives. It is common knowledge that a wall socket in a home in the United States is 120 VAC, but did you know that the peak voltage from that wall socket is 170 volts? That fact is simply a characteristic of AC that is described in this module. A technician must have in-depth knowledge of AC generation, characteristics, and measurement to maintain and troubleshoot industrial equipment effectively.