What is the primary function of a diode?

The primary function of a diode is to direct electrical power in one direction, acting as a one-way valve for electric current. This means that when voltage is applied in the forward direction, the diode conducts electricity, allowing current to flow through it. Conversely, when voltage is applied in the reverse direction, the diode blocks current from flowing, effectively preventing it from passing through.

This unidirectional behavior is essential for many applications, such as in rectifiers where alternating current (AC) needs to be converted into direct current (DC). By ensuring that current flows consistently in one direction, diodes help protect circuits and control the flow of electricity in various electronic devices.

The other functions mentioned do not accurately characterize the main role of a diode; while measuring voltage, storing electrical energy, or converting power can be functions of other components in an electrical system, they do not adequately explain the key characteristic of how a diode operates.