Which of the following statements is true regarding circuit capability?

When discussing circuit capability, it's important to understand the characteristics of different types of loads. Continuous loads are those that operate for three hours or more at their rated load. These types of loads can potentially draw significant power over time, which makes careful consideration of their wattage crucial to avoid overheating and ensure that the circuit can handle the sustained load without tripping breakers or causing damage.

Therefore, when planning or evaluating circuits with continuous loads, it's essential to account for their power consumption accurately. This consideration includes ensuring that the circuit has the appropriate wire gauge, breaker size, and overall capacity to handle the prolonged use without exceeding safe limits. This is why focusing on wattage for continuous loads is fundamental to ensuring safety and functionality in residential wiring.

Other choices incorrectly represent circuit capabilities or safety standards. Some circuits can support both continuous and non-continuous loads, a branch circuit can often feed multiple load types as long as they are within the circuit's capacity, and circuits can operate at various voltage ratings beyond just 120 volts depending on the application and design.