What does a Volt measure?

A volt measures the electrical potential difference or electromotive force in a circuit, which is directly related to the rate at which electrical energy is delivered. It quantifies how much potential energy exists to cause a flow of current through a resistance. This understanding is crucial for estheticians who utilize electrical devices in treatments; knowing the appropriate voltage ensures that the equipment operates safely and effectively.

While the other options mention aspects of electricity, they relate to different measurements. Resistance is measured in ohms, current flow is measured in amperes, and energy consumption is typically expressed in watt-hours. Thus, the identification of volts specifically as the rate of current delivery aligns with its definition in the context of electromotive force in circuits.