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 in a p-n junction diode is very small until the breakdown voltage is reached, after which the current increases rapidly.

Answer 1

Step 1: V-I Characteristics of a p-n junction.
In a p-n junction diode, when reverse bias is applied, the current is very small until the reverse voltage reaches a certain point, called the breakdown voltage.
Step 2: Understanding reverse bias.
In reverse bias, the positive terminal of the battery is connected to the n-type material and the negative terminal to the p-type material. This causes the depletion region to widen, and the current remains very small (called the reverse leakage current).
Step 3: Breakdown voltage.
If the reverse bias is increased beyond a certain point (breakdown voltage), the diode experiences a sharp increase in current due to avalanche breakdown or Zener breakdown. The V-I characteristic shows a steep rise in current after reaching the breakdown voltage.
Step 4: Circuit diagram.
The circuit diagram for reverse biasing of a p-n junction diode is: \[ \text{[Insert diagram of a circuit with a p-n junction diode in reverse bias]} \] The V-I characteristic curve would show a very small current initially and then a sharp increase once the breakdown voltage is reached.
Step 5: Conclusion.
In reverse bias, the current through a p-n junction diode remains very small until the breakdown voltage is reached, beyond which the current increases sharply.