Which equipment provides an overcurrent protection mechanism in residential buildings?

The correct choice is circuit breakers or fuses, as they are specifically designed to provide overcurrent protection in residential electrical systems. When the current flowing through a circuit exceeds its rated capacity, either due to a fault condition or an overload, these devices will interrupt the flow of electricity.

Circuit breakers achieve this by automatically shutting off the electric flow to prevent damage to the wiring and connected devices, while fuses do so by melting a conductive element, breaking the circuit. Both serve the critical function of protecting equipment, preventing overheating, and reducing the risk of electrical fires.

The other options, such as transformers, receptacles, and disconnect switches, do not provide overcurrent protection. Transformers are used for voltage conversion, receptacles serve as connection points for electrical devices, and disconnect switches are utilized for isolating circuits for maintenance or emergency situations. Therefore, they do not serve the primary role of mitigating overcurrent situations in electrical installations.