Polarized capacitors are used primarily in which type of circuits?

Polarized capacitors are specifically designed for use in direct current (DC) circuits. This is because they have distinct positive and negative terminals, and applying voltage in the wrong direction can lead to failure or even explosion. In DC circuits, there's a constant flow of current in one direction, which aligns perfectly with the operational design of polarized capacitors.

In contrast, alternating current (AC) circuits continuously change direction, which could stress the polarized capacitor by constantly reversing the voltage polarity. While polarized capacitors may be found in mixed circuits under specific conditions, it's primarily in DC circuits that their unique characteristics are utilized effectively. This specialized use is what makes DC circuits the optimal application for polarized capacitors.