A power system fault typically decreases ________ and increases __________.

In a power system, when a fault occurs, such as a short circuit, the electrical characteristics of the system change significantly. The correct answer highlights the relationship between voltage, current, and fault conditions.

During a fault, the impedance in the circuit is effectively reduced because a short circuit provides a lower resistance path for current to flow. As a result, the current flowing through the system increases significantly because of the reduced impedance. This increase in current is due to Ohm's Law, where current is inversely proportional to impedance.

Simultaneously, the voltage in the affected area tends to decrease. This is because power system faults create conditions where the normal voltage levels cannot be maintained due to the sudden influx of current and the electrical disturbances that occur. The disruption caused by the fault does not allow the system to stabilize, leading to a drop in voltage.

Therefore, the dynamics of a power system during a fault lead to a decrease in voltage and an increase in current, confirming the correctness of the selected choice.