NCIDQ IDFX Practice Exam

Which of the following is a characteristic of incandescent lighting?

1. High efficacy and long lamp life

2. Warm color rendition but low efficacy

3. High lumens per watt and cool color temperature

4. High heat output but energy efficient

The correct answer is: Warm color rendition but low efficacy

Incandescent lighting is known for its warm color rendition, which typically occurs at a color temperature around 2700K to 3000K. This characteristic gives incandescent bulbs a pleasant, inviting glow that is favored in many residential and hospitality settings where aesthetics and comfort are prioritized. In terms of efficacy, incandescent bulbs are relatively low compared to other lighting technologies, such as fluorescent or LED, which produce more light (lumens) per watt of electricity consumed. Therefore, while incandescent lighting can create a warm atmosphere, it does so with a lower energy efficiency, leading to higher energy costs over time. The other options do not align with the traits of incandescent lighting. High efficacy and long lamp life are attributes found more often in LED and fluorescent lighting, while the idea of high lumens per watt and a cool color temperature is also not applicable to incandescent bulbs, which typically operate with a warm rather than cool color temperature. High heat output does occur with incandescent lighting, but it is not considered energy efficient. Thus, the choice highlights the distinct warmth and efficiency deficiencies commonly associated with incandescent bulbs.