Step 1: Understanding reverse biased diodes.
A diode is reverse biased when the positive terminal of the power supply is connected to the cathode and the negative terminal to the anode. This prevents current from flowing. In reverse bias, certain diodes exhibit specific characteristics.
Step 2: Explanation of each option.
- (A) Zener diode: Correct. A Zener diode is typically used in reverse bias to maintain a stable voltage across it. It is designed to break down at a certain reverse voltage, allowing current to flow.
- (B) LED: Incorrect. An LED (Light Emitting Diode) operates in forward bias, where current flows from anode to cathode, emitting light.
- (C) Photodiode: Correct. A photodiode operates in reverse bias and generates current when exposed to light.
- (D) both (A) and (C): Correct. Both Zener diodes and photodiodes operate in reverse bias.
Step 3: Conclusion.
Reverse biased diodes include both Zener diodes and photodiodes.