question_answer

Figure shows the \[\mathbf{V}-\mathbf{I}\] characteristic of a semiconductor diode. (i) Identify the semiconductor diode used. (ii) Draw the circuit diagram to obtain the given characteristic of this device. (iii) Briefly explain how this diode can be used as a voltage regulator.         

Answer:

                    (i) Zener diode. (ii) Figure (a) shows circuit diagram for forward biasing and Fig. (b) for reverse  biasing of Zener diode. (iii) Figure shows the circuit diagram for using Zener diode as a voltage regulator. When Zener diode is operated in the reverse breakdown region, the voltage across it remains practically constant \[({{V}_{Z}})\] for a large change in reverse current. So any increase/decrease of the input voltage results in, increase/ decrease of the voltage drop across \[{{R}_{s}}\] without any change in voltage across Zener diode. Hence the Zener diode acts as a voltage regulator.