Which of the following features characterizes a complete lighting unit?

A complete lighting unit is characterized by the integration of all necessary components that work together to produce light effectively. This includes not just the light bulb, which generates illumination, but also a power supply that provides the necessary electrical energy, and essential elements like a reflector and housing that help distribute and protect the light source.

The light bulb alone is insufficient because it requires a power supply to operate. The power supply is crucial as it converts electrical energy into light, but without the bulb, it would not perform its intended function. Likewise, reflectors and housing play vital roles in managing the light output by directing it towards the desired area and providing safety and support for the bulb.

Therefore, all components together create a complete lighting unit that functions successfully and meets lighting needs, highlighting the importance of each part in the assembly.