Putting phosphors inside a sodium lamp is a poor idea because
A) It takes high energy light to make the phosphors glow and sodium does not produce enough of it.
B) They will be too bright for commercial use.
C) Their color cannot be controlled
D) The sodium vapor will react adversely with the phosphors.

Question

Quizplus · Accepted Answer

Sodium lamps emit light at a relatively low energy level, primarily in the yellow part of the spectrum. Phosphors require higher energy light, typically in the ultraviolet range, to be excited and emit visible light. Since sodium lamps do not produce sufficient high-energy light, phosphors would not be effectively excited to glow, making it a poor combination.

Putting Phosphors Inside a Sodium Lamp Is a Poor Idea