What is the function of a diode?

What is the function of a diode?

• A. Allows current to flow in both directions
• B. Stores energy
• C. Permits current to flow in only one direction
• D. Converts alternating current to direct current

Answer: (C)

Diodes are unidirectional devices. A PN junction creates a barrier that conducts when the anode is positive relative to the cathode (forward bias), allowing current to flow with relatively low resistance. When the polarity reverses (reverse bias), the barrier widens and the current is almost blocked, except for a tiny leakage. This one-way conductance is what makes diodes useful for steering current, protecting circuits, and enabling rectification in power supplies. The other statements describe properties of other components (storing energy like capacitors/inductors, or converting AC to DC by a circuit rather than by the diode alone), which is why they’re not the function of a diode.

Diodes are unidirectional devices. A PN junction creates a barrier that conducts when the anode is positive relative to the cathode (forward bias), allowing current to flow with relatively low resistance. When the polarity reverses (reverse bias), the barrier widens and the current is almost blocked, except for a tiny leakage. This one-way conductance is what makes diodes useful for steering current, protecting circuits, and enabling rectification in power supplies. The other statements describe properties of other components (storing energy like capacitors/inductors, or converting AC to DC by a circuit rather than by the diode alone), which is why they’re not the function of a diode.