Common household breakers are typically set to trip at what level of current?

The correct choice of 10-30 mA reflects the typical current range at which household ground fault circuit interrupters (GFCIs) are designed to trip. These devices are essential for protecting against electrical shocks by monitoring the current flowing through a circuit. If an imbalance is detected—indicating a potential leak of current to the ground, which could cause electric shock—the GFCI trips and cuts off the power to prevent harm.

The 10-30 mA range is particularly effective because it is sensitive enough to detect minor leaks, thereby minimizing risks while being designed to avoid nuisance tripping from harmless variations in current. This is an important safety aspect in residential settings, where users might be at risk from wet conditions or other hazards.

Other ranges listed do not align with standard GFCI settings for household use. While lower thresholds may provide added safety, they could lead to excessive tripping from minor fluctuations that don't pose a safety risk. Higher settings would compromise safety by allowing greater current leaks before tripping occurs. Thus, the chosen range of 10-30 mA effectively balances sensitivity with reliability in household applications.