What mechanism is used to measure electrical energy in a building?

The kilowatt-hour meter is the correct mechanism for measuring electrical energy in a building because it quantifies the total energy consumed over time, specifically in kilowatt-hours. This type of meter tracks the amount of electrical energy used by accurately measuring both voltage and current over a specified duration, allowing it to provide a comprehensive view of energy consumption.

In residential and commercial settings, this measurement is essential for billing purposes, as utility companies charge customers based on the kilowatt-hours consumed. Therefore, the kilowatt-hour meter becomes crucial for both energy management and economic reasons, ensuring individuals and businesses are charged appropriately for their electrical usage.

Other devices, such as hydro meters, primarily deal with water consumption rather than electrical measurements. Amperage meters measure current flow but do not account for voltage, which is necessary for calculating energy consumption. Voltage meters measure the potential difference in electricity but do not provide a direct correlation to energy consumed over time. Thus, the kilowatt-hour meter stands out as the most appropriate tool for measuring electrical energy in a building.