Which type of diode allows current to flow in one direction only?

Which type of diode allows current to flow in one direction only?

• A. Photodiode
• B. Rectifier diode
• C. Zener diode
• D. Schottky diode

Answer: (B)

The rectifier diode is specifically designed to allow current to flow in one direction only, making it fundamental in applications such as converting alternating current (AC) to direct current (DC). This unidirectional behavior is achieved through the diode's internal structure, which consists of a p-n junction. When a forward voltage is applied, it reduces the barrier and allows current to pass. Conversely, when the voltage is reversed, the depletion region widens, preventing current from flowing. In contrast, other types of diodes, such as photodiodes, Zener diodes, and Schottky diodes, have distinct characteristics that cater to different applications. A photodiode is sensitive to light and generates a current when exposed to it. A Zener diode is designed to allow current to flow in the reverse direction at certain voltage ratings, effectively functioning as a voltage regulator. A Schottky diode, while also allowing current to flow in one direction, is optimized for high-speed applications due to its low forward voltage drop and fast switching capabilities. Each of these diodes serves unique purposes but does not specifically fulfill the primary role of rectifying current as the rectifier diode does.

The rectifier diode is specifically designed to allow current to flow in one direction only, making it fundamental in applications such as converting alternating current (AC) to direct current (DC). This unidirectional behavior is achieved through the diode's internal structure, which consists of a p-n junction. When a forward voltage is applied, it reduces the barrier and allows current to pass. Conversely, when the voltage is reversed, the depletion region widens, preventing current from flowing.

In contrast, other types of diodes, such as photodiodes, Zener diodes, and Schottky diodes, have distinct characteristics that cater to different applications. A photodiode is sensitive to light and generates a current when exposed to it. A Zener diode is designed to allow current to flow in the reverse direction at certain voltage ratings, effectively functioning as a voltage regulator. A Schottky diode, while also allowing current to flow in one direction, is optimized for high-speed applications due to its low forward voltage drop and fast switching capabilities. Each of these diodes serves unique purposes but does not specifically fulfill the primary role of rectifying current as the rectifier diode does.