What is a receptacle outlet?

A receptacle outlet is a point for connecting electrical devices to the power supply, which is why the selected answer is correct. It allows users to plug in appliances or equipment to receive electrical power in a safe and convenient manner. Receptacles are designed for easy access and may accommodate various plug types depending on their specifications, enabling a versatile connection to the electrical system.

In contrast, a permanent fixture supplying constant power does not accurately describe a receptacle outlet, as receptacles facilitate temporary connections rather than providing power on a fixed basis. Similarly, a device that detects electrical faults refers to ground fault circuit interrupters or similar protective equipment, which is distinct from the basic function of a receptacle. Lastly, a safety device that cuts off power pertains to circuit breakers or fuses, which serve to protect the electrical system but do not define the purpose of a receptacle outlet. Each of these other options represents different aspects of electrical systems but does not encapsulate the specific functionality of a receptacle outlet.