question_answer

In the following circuits, if the input waveform is as shown in the figure, what will be the output wave from, (i) across R in Fig. (a), and (ii) across the diode in Fig. (b)? Assume that the diode is ideal.                                        

Answer:

                    (i) When the input level is \[-\text{ 5 V},\] the diode gets reverse biased. No output is obtained across R. When the input level becomes \[+\text{ 5 V},\] the diode gets forward biased and current flows through R. As the diode is ideal, the output across R will be exactly \[\text{5 V},\] as shown in at Fig. (a). (ii) When the input level is\[-\text{ 5 V}\], the diode remains reverse biased. It does not conduct current. This part of S input wave appears across the diode as shown in Fig. (b). When the input level is \[+\text{ 5 V},\] the diode gets forward biased and conducts currents. As the diode is ideal, no voltage appears across it.