Assuming safe levels, which type of current would break a light bulb's filament quicker?

To understand why alternating current (AC) would break a light bulb's filament quicker than direct current (DC), we need to consider the characteristics of each type of electrical current.

In AC, the voltage fluctuates and reverses direction periodically, which means that the current is not constant. This variation in voltage can produce higher thermal stresses on the filament because it heats up and cools down repeatedly as the current alternates. The continuous heating and cooling cycle contributes to metal fatigue in the filament material, leading to a higher likelihood of breakage.

On the other hand, DC provides a steady and constant current flowing in one direction. While DC can still cause wear over time, the absence of fluctuations means that the filament experiences a more uniform heating. This stability generally allows the filament to last longer compared to when subjected to AC.

The other options, like "both AC and DC equally" or "neither, it depends on the voltage," do not correctly account for the different effects of alternating versus direct current on the filament. While voltage does play a role in how much current flows and how much heat is generated, the primary factor in this scenario is the nature of AC and how its fluctuating current affects the longevity of the filament.