question_answer 21)

  In Fig. 9(EP).1, V0 is the potential barrier across a p-n junction, when no battery is connected across the junction (a) 1 and 3 both correspond to forward bias of junction (b) 3 corresponds to forward bias of junction  and 1 corresponds to reverse bias of junction (c) 1 corresponds to forward bias and 3 corresponds to reverse bias of junction           (d) 3 and 1 both correspond to reverse bias of junction

Answer:

                                                        (b) When p-n junction is forward biased, it opposes the potential harder across junction. When p-n junction is reverse biased, it supports the potential barrier junction, resulting increase in potential barrier across ; the junction. Thus, option (b) is correct.