Question

With the help of a circuit diagram, explain the V-I characteristics of a p-n junction in reverse biasing.

Hint:

In reverse bias, the current remains very small until the breakdown voltage is reached, after which the current increases rapidly due to breakdown.

Answer 1

Step 1: Reverse Biasing of a p-n Junction Diode.
In reverse bias, the positive terminal of the battery is connected to the n-type material of the diode, and the negative terminal is connected to the p-type material. This causes the depletion region to widen, and the current becomes very small (called reverse leakage current).
Step 2: V-I Characteristics.
The current in a p-n junction diode under reverse bias remains very small up to a certain voltage. When the reverse voltage reaches the breakdown voltage, the current increases drastically due to processes like avalanche breakdown or Zener breakdown.
Step 3: Diagram of the circuit.
\[ \text{[Insert diagram of a p-n junction diode in reverse bias]} \] In the diagram, the p-n junction diode is placed in a reverse-biased circuit. Initially, no current flows, but once the voltage exceeds the breakdown voltage, a large current flows.
Step 4: Conclusion.
In reverse bias, the current remains very small until the breakdown voltage is reached. After that, the current increases rapidly.