ESCO Electrical Employment Ready Practice Test

Diodes act as one-way gates for electric current. In a DC circuit, a diode conducts when the anode is more positive than the cathode by a small forward threshold (about 0.7 V for silicon), and it blocks current in the opposite direction. This single-direction flow is why diodes are used to protect circuits from reverse polarity and to convert alternating current to direct current in rectifier circuits. The other descriptions describe different components or functions: storing charge is what a capacitor does, stepping voltage up is done by a transformer or boost converter, and while diodes can be part of AC rectification, their primary role isn’t to “control AC switching” in general.