A Potentiometer Circuit can be use in studying the vi characteristics of a pn junction diode in forward and reverse bias.
Potentiometer Circuit setup offers finer control over the voltage applied to the diode. The diode is connected in series with a resistor, an ammeter, and a potentiometer. Potentiometer circuit for forward bias of a PN junction diode is achieved by adjusting the potentiometer, we can change the voltage across the diode and measure the resulting current with the ammeter.
The Reverse bias circuit of a PN junction diode can also be used. In reverse bias, the current reading will be much smaller compared to forward bias and we accurately measure the small leakage current in reverse bias, a high-sensitivity ammeter or a current-to-voltage converter (I-V converter) is typically used in conjunction with the basic series circuit.