question_answer

(i) Give the V-I characteristics of p-n junction diode.

(ii) The Zener diode is fabricated by heavily doping of both p and n-sides of junction. Give reason.

(iii) A 200 V AC supply is connected between points A and B as shown in the figure. What will be the potential difference V across the capacitor?

Or In the figure given below, circuit symbol of a logic gate and two input waveforms A and B are shown. Circuit symbol Input waveform

(i) Name the logic gate.

(ii) Write its truth table.

(iii) Give the output waveform.

Answer:

            (i) The \[V-I\] characteristics of p-n junction diode is given below: (ii) The both p and n- sides of Zener diode is heavily doped, because due to this depletion region so formed is very thin \[(<{{10}^{-6}}m)\] and the electric field of the junction is extremely high \[(-5\times {{10}^{6}}V/m)\]  even for a small reverse bias voltage of about 5 V. (iii) As, p-n junction diode conducts electricity during only half cycle (or forward bias condition). So, potential difference across C = Peak voltage of the given AC voltage, i.e. \[{{V}_{0}}={{V}_{rms}}\times \sqrt{2}=200\times \sqrt{2}=200\sqrt{2}V\] Or (i) AND gate. (ii) Truth table of AND gate is

A	B	\[Y=A\cdot B\]
0	0	0
0	1	0
1	0	0
1	1	1

(iii) Output waveform