NALMCO Certified Apprentice Lighting Technician (CALT) Practice Exam

A lighting system's efficacy is measured in?

1. Lumens/Watt

2. Amps/Volt

3. Lumens/kWh

4. $/kWh

The correct answer is: Lumens/Watt

The efficacy of a lighting system is measured in lumens per watt. This metric indicates how efficiently a lighting system converts electrical energy (measured in watts) into visible light (measured in lumens). A higher lumens per watt ratio signifies a more efficient lighting system, meaning that it produces more light while consuming less electricity. This measure is crucial for comparing different lighting technologies, as it helps determine which sources provide more illumination for less energy consumption, ultimately leading to cost savings and reduced environmental impact. While other options involve electrical measurements, they do not directly relate to the efficiency of light output for a given power consumption. Amps per volt relates to electrical power calculation rather than illumination efficiency, while lumens per kilowatt-hour pertains more to energy consumption over time rather than instantaneous efficacy. Lastly, dollars per kilowatt-hour focuses on cost rather than the actual output of light given the input of power.