Why do light bulbs blow?

Question

Just wondering why they always blow

Answer 1

If you're asking why the typical incandescent bulb (usually abt 60 watts) in residential light fixtures "blow" when they're turned on... then this is your answer.

Those typical bulbs provide light by allowing the electric current (110-120 volts alternating current) to heat a small tungsten filament to white heat (rather inefficient, because so much energy is lost to heat). When the filament is cold its resistance is significantly less than when it's operational. That lower resistance means that when the bulb is first turned on more "juice" runs thru the filament than when it's operating as it's supposed too. Over time this start up surge, along with the heat stress to the tiny filament and any shock stressing that can affect the filament will cause the bulb to "blow" -- frequently on start up, but not always.