Question

In a typical American building, most modern lighting systems must use what voltage?

A. S V
B. 48 V
C. 120 V
D. 250 V

Answer 1

Typically, either 110-volt AC (110V) or 220-volt AC (220V) is used. Most countries use 50Hz (50 Hertz or 50 cycles per second) as their AC frequency. Only a handful use 60Hz. The standard in the United States is 120V and 60Hz AC electricity.