NALMCO Certified Apprentice Lighting Technician (CALT) Practice Exam

Incandescent lamps typically provide how many hours of service life?

1. 2000 ; 4000

2. 1000 ; 4000

3. 750-1000 ; 1500-3000

4. 800-2000 ; 2000-4500

The correct answer is: 750-1000 ; 1500-3000

The service life of incandescent lamps is generally understood to range from 750 to 1000 hours for most standard applications. This range reflects the typical lifespan before they begin to fail. Additionally, there are variations in meticulous manufacturing processes and materials which can extend the life further, but the standard expectation does not exceed these figures significantly. The upper range provided in the correct choice, 1500 to 3000 hours, applies more to specialty incandescent bulbs or higher-quality designs, which is somewhat atypical but still relevant in discussions where extended life might be a selling point. Hence, this option accurately captures the common service life expectations surrounding incandescent lamps, taking into consideration both average and potentially enhanced lifetimes, making it the most suitable choice among the given options.