Exam 1 question 19

Hi @coachadamcoers can you explain the answer to this question?
I thought HID’s like metal halide lighting are used for outdoor use, stadiums or gyms, because they take a while to turn on, is that correct? I guess that’s the better answer compared to the other ones.

An architect is specifying lighting for a high-end jewelry store.

Which light sources should the architect consider? Check the three that apply.

Compact fluorescent (CFL)

Incorrect. CFLs do not have a high color rendering index (CRI) and are not appropriate for this situation.

Tungsten halogen

Correct. Tungsten halogen bulbs offer a focused light and a high color rendering index (CRI).


Correct. LEDs can offer a high color rendering index (CRI) and are energy efficient and versatile, making them a good option.

T8 fluorescent

Incorrect. T8 fluorescent bulbs do not have a high color rendering index (CRI) and are not appropriate for this situation.

Metal halide

Correct. Metal halide lights offer a high color rendering index (CRI) and are often used in retail stores.


Incorrect. Neon lights are brightly glowing tubes that are used for novelty lighting applications. Neon is not a source of lighting for a retail application.

Reference: Mechanical & Electrical Equipment for Buildings


What this particular question is testing on is the different characteristics of each of these types of light sources. When you are looking at a retail location, especially a high end jewelry store, how an item looks under light is very important as colors could be distorted otherwise; so for this question we would want to look for lighting types that have a high color render index or CRI - the higher the CRI, the better the colors look. Tungsten Halogens, LED’s and Metal Halides all have a very high CRI compared to the fluorescent options.

While the metal halides are more typically used in outdoor application and do take awhile to turn on, you want to pay close attention to the question stem. It is asking you which should the architect consider, not select; so the question is asking you to evaluate based on characteristics/properties, not necessarily applications. I’m not sure if you are into sports or not, but think about this kind of like a tournament bracket… and right now this question is “populating the field” by evaluating whether or not the light source has the criteria to compete. Further considerations will take place to narrow the contenders until one remains, which is the one that would ultimately be used in the application.

Hopefully this helps. You were definitely on the right track with your last thought though about which is the better answer. The ARE can be tricky like that so it’s important to carefully analyze what the question is asking.

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