In which operation state does a diode exhibit high resistance and does not conduct electricity?

A diode exhibits high resistance and does not conduct electricity in a reverse bias condition. In this state, the diode is oriented such that the positive voltage is applied to the n-type material and the negative voltage to the p-type material. This arrangement prevents current flow, allowing only a very small leakage current, if any, to occur. This high resistance is a fundamental characteristic of diodes when reverse biased, thus making them essential in applications like rectifiers and voltage blocking circuits.

In forward bias, the diode allows current to flow easily, creating low resistance. A short circuit refers to a connection that allows current to flow along an unintended path, typically resulting in very low resistance. An open circuit means there is a break in the path for current, which also results in no current flow, but it is not specifically associated with the diode’s operating principles in the same context as reverse bias. Therefore, the correct answer captures the nature of diode behavior under reverse bias conditions.