(a) To A.C
(b) In forward bias
(c) In reverse bias
(d) None of these
When the PN junction diode is connected in reverse bias no current flows and works as an insulator.
When a p-n junction diode is used for blocking the electric current in the presence of applied voltage, then the diode is said to a reverse-biased p-n junction diode.
In a reverse-biased p-n junction diode, the n-type semiconductor is connected to the positive terminal of the battery while p-type semiconductor is connected to the negative terminal of the battery.