An industrial power socket in a European factory delivers an alternating current (AC) supply rated at 400 V400\text{ V}400 V.
Which of the following statements is correct?
The mean voltage is 283 V283\text{ V}283 V.
The peak voltage is 400 V400\text{ V}400 V.
The root mean square voltage is 566 V566\text{ V}566 V.
The peak-to-peak voltage is 1131 V1131\text{ V}1131 V.