What happens in an electrical circuit when a diode is reverse biased?

When a diode is reverse biased, it means that the polarity of the voltage across the diode is such that it blocks current flow from the anode to the cathode. In this configuration, the diode essentially acts as an insulator. The reverse voltage increases the depletion region within the diode, preventing current from passing through it under normal conditions.

The diode will only conduct in the reverse direction under certain circumstances, such as when the reverse voltage exceeds the breakdown voltage, which can lead to potentially damaging conditions. Therefore, due to this characteristic behavior of diodes in reverse bias, they are commonly used for protection against reverse polarity in circuits, which reinforces the notion that the voltage is effectively blocked from allowing current to flow.

This behavior is instrumental in various applications including rectification and signal modulation, where control over current direction is essential for circuit functionality.