which feature a wire filament encased in a glass bulb, were once the standard in most homes. But because they’ve got a short life span and aren’t energy efficient, incandescent light bulbs ...

We tested the low-beam performance of single-filament (9003) and dual-filament (H7) bulbs from GE, Hella, Philips, and Sylvania, and PIAA's dual-filament bulb. We also compared their performance ...

through the plug, and into a device such as a radio or TV. In a light bulb, the metal filament conducts electricity and causes the light bulb to light up.