What is the typical voltage of a residential branch circuit in the US?

What is the typical voltage of a residential branch circuit in the US?

• A. 120 VAC nominal.
• B. 240 VAC.
• C. 12 VDC.
• D. 120/240 VAC.

Answer: (A)

The typical branch circuit in a US home provides about 120 volts AC. This comes from the split-phase service where each branch circuit uses one hot leg relative to neutral, giving roughly 120 V. The two hot legs are opposite in phase, so between them you’d have 240 V, which is why large appliances use dedicated 240 V circuits. The voltage can vary a bit in practice (often around 114–125 V), but 120 V nominal is the standard for lighting and receptacle circuits. DC is not used for these standard branch circuits. That’s why the correct choice is 120 VAC nominal.

The typical branch circuit in a US home provides about 120 volts AC. This comes from the split-phase service where each branch circuit uses one hot leg relative to neutral, giving roughly 120 V. The two hot legs are opposite in phase, so between them you’d have 240 V, which is why large appliances use dedicated 240 V circuits. The voltage can vary a bit in practice (often around 114–125 V), but 120 V nominal is the standard for lighting and receptacle circuits. DC is not used for these standard branch circuits. That’s why the correct choice is 120 VAC nominal.