Industrial Electrician Practice Test 2025 – Comprehensive Exam Prep

The typical voltage of a residential electrical system in North America is indeed 120 volts. This voltage level is standardized for most household outlets and is the nominal voltage used for powering most common household appliances, lighting, and electronics.

In residential systems, electrical panels are generally designed to distribute both 120 volts and 240 volts. The 120-volt supply is derived from the splitting of a 240-volt supply line, with two hot wires (with one being neutral) allowing for this lower voltage. This configuration ensures that sensitive devices, such as computers and small appliances, can operate safely and efficiently.

In contrast, higher voltages like 240 volts are typically used for larger appliances such as dryers and ovens, which require more power for operation. The other options, such as 480 volts and 600 volts, are commonly found in industrial settings for heavy machinery and equipment but are not standard for residential systems.