Question

Why do not tube light generate heat

Answer 1

Explanation:

Tube lights dissipate heat which means that the power that they use to light up, is consumed and as the first law of thermodynamics goes, energy can neither be created nor be destroyed but only transformed into another form

Answer 2

The interaction of electricity and argon vapour along with a bit of mercury creates a plasma arc, and the arc radiates energy out of it, and the phosphors on the outside of the tube glow. The glow converts the electrical plasma energy into light , and heat, but not much.

Another type of tube light is a Vacuum Display device.

Both are deemed ‘cold ‘ devices since they do not get as ‘hot’ as incandescent bulbs do.