Define "ampacity."

Ampacity refers to the maximum amount of electric current a conductor or device can carry before exceeding its temperature rating. This is a crucial concept in electrical work, as it helps ensure safety and efficiency in electrical installations. Properly understanding ampacity allows electricians to select the right wire gauge for a specific application, preventing overheating and potential fire hazards.

The other options describe different aspects of electrical science but do not define ampacity. The speed of electrical flow pertains to the propagation of an electrical signal rather than the current capacity of a conductor. Resistance in a circuit is related to how much the circuit opposes the flow of current, and the voltage rating specifies the maximum voltage a circuit can handle without breaking down. While all these aspects are important in electrical engineering, ampacity is specifically focused on the current-carrying capacity, making it a fundamental consideration for safe electrical design and installation.