Question

What is common to all light sources, including incandescent, fluorescent, neon, halogen, laser, and sodium-vapor devices?

Answer 1

The correct answer of this question is : Artificial luminous sources.

EXPLANATION :

As per the question, we are given some light sources like halogen, laser, sodium-vapor etc.

There are two types of bodies which are known as luminous and non luminous depending on their production of light.

All these sources given in the question are luminous sources as they have their own light. Most importantly they are not natural luminous sources like stars, firefly etc.

All these sources are artificial.

Hence, the correct answer of this question is artificial luminous sources.

Answer 2

The common thing to all light sources, including incandescent, fluorescent, neon, halogen, laser, and sodium-vapor devices is that all of them are artificial light sources.