How do car bulbs work?
Despite being smaller than the bulbs you'll find in your lampshades at home, car bulbs are much brighter and longer lasting than the bulbs used to light up your living room.
They can, however, use the same technology; just like household bulbs, the filament within car light bulbs heats up when an electric current passes through it, and then produces light to project onto the road ahead of you. Halogen car light bulbs work in a similar way, but there are other types of bulbs on the market that work differently, such as LED bulbs which emit virtually no heat at all.
The primary function of any bulb is to beam light out onto the road directly ahead of it, while the intensity of that light is amplified by super-reflective materials that surround the bulb within the headlight itself.
If you take your rear lights, for example, the red effect they create is typically achieved through having a red-coloured plastic cover over the bulb itself, unless you have a specific LED emitting red light. Similarly, orange plastic films help other drivers see that you’re indicating.