NALMCO Certified Apprentice Lighting Technician (CALT) Practice Exam

Which statement about compact fluorescent lamps (CFLs) with screw-in bases is accurate?

1. They have a warm color temperature

2. They are shatter-proof

3. They are preheat lamps

4. They are self-ballasted

The correct answer is: They are self-ballasted

Compact fluorescent lamps (CFLs) with screw-in bases are classified as self-ballasted lamps. This means that they contain an integrated ballast within the lamp itself, allowing them to be directly screwed into standard light fixtures without the need for an external ballast. This feature contributes to their convenience and ease of installation, making them user-friendly for consumers and useful in a variety of applications. The other characteristics of CFLs can vary. For instance, while some CFLs may produce a warm color temperature, others are available in cooler tones, which would not make that statement universally accurate. The term "shatter-proof" can be misleading; CFLs are made of glass and can break, though some designs may include protective covers to reduce the risk of shattering. Furthermore, CFLs are not categorized as preheat lamps; they typically start instantly or with a slight delay, differentiating them from traditional fluorescent lamps that require a preheating period to ignite. Therefore, the self-ballasted nature of CFLs stands out as the defining and accurate characteristic in the given context.