What feature differentiates a duplex receptacle from a standard receptacle?

A duplex receptacle is distinguished by its design, specifically by having two plug-in spaces that allow for two electrical devices to be plugged in simultaneously. This design is particularly beneficial in terms of convenience, as it saves space and reduces the need for multiple outlets in a single area.

In contrast, a standard single receptacle typically has only one plug-in space, making it less versatile for accommodating multiple devices. This feature is a common characteristic of duplex receptacles found in many residential and commercial environments to meet the demand for power supply in an efficient manner.

The other features listed do not specifically define a duplex receptacle. Higher voltage ratings, frequency of electrical flow, and increased amperage capacity are characteristics that may apply to various types of electrical devices or receptacles, but they do not distinctly separate duplex receptacles from standard ones. Focusing on the design difference provides a clear understanding of why having two plug-in spaces is the unique feature of a duplex receptacle.