NCIDQ IDFX Practice Exam

Which fluorescent lamp type is more popular due to higher efficacy?

1. T4 and T5

2. GU-24

3. Tungsten Halogen

4. MR-16

The correct answer is: T4 and T5

The type of fluorescent lamp that is more popular due to higher efficacy is the T4 and T5 lamps. These specific lamp types offer a greater amount of light output relative to the amount of energy they consume, which is a key measure of efficacy. Efficacy is expressed in lumens per watt, and higher efficacy means greater efficiency in providing illumination. T4 and T5 fluorescent lamps are designed to be more compact than traditional fluorescent tubes, allowing for efficient use of space in fixtures and improved performance in applications where size and weight are concerns. This compact design also contributes to a more effective distribution of light, enhancing the overall illumination quality. Because of these features, T4 and T5 lamps are widely used in commercial and residential settings, making them a popular choice for energy-efficient lighting solutions. In contrast, options like GU-24, Tungsten Halogen, and MR-16, while useful in specific applications, do not match the efficacy offered by T4 and T5 fluorescent lamps. GU-24 is a base type for compact fluorescent and some LED lamps, but it focuses more on socket design rather than the lamp's efficacy itself. Tungsten Halogen and MR-16 lamps primarily use a different technology (incandescent) that tends