Question 17.AP.2: Lightbulb Failures Why do lightbulbs fail so often immediate...

Once the switch is closed, the line voltage is applied across the bulb. As the voltage is applied across the cold filament when the bulb is first turned on, the resistance of the filament is low, the current is high, and a relatively large amount of power is delivered to the bulb. This current spike at the beginning of operation is the reason lightbulbs often fail immediately after they are turned on. As the filament warms, its resistance rises and the current decreases. As a result, the power delivered to the bulb decreases and the bulb is less likely to burn out.