What constitutes the reverse current? (A) holes in both \(\mathrm{p}\) and \(\mathrm{n}\) type. (B) free electrons in both \(\mathrm{p}\) and \(\mathrm{n}\) type (C) free electrons in p-type and holes in n-type (D) holes in p-type and free electrons in n-type.

To begin with, let's recall what p-type and n-type semiconductors are: - In a p-type semiconductor, the majority charge carriers are holes, created by the substitution of atoms that have fewer valence electrons. This results in an excess of positive charge. - In an n-type semiconductor, the majority charge carriers are free electrons, created by the substitution of atoms that have extra valence electrons. This results in an excess of negative charge. When a diode is reverse-biased, the majority charge carriers become separated from each other, and only a small amount of charge can flow as the reverse current, caused by minority carriers.

Now that we know about majority charge carriers in p-type and n-type semiconductors, we can identify the minority carriers involved in the reverse current: - In a p-type semiconductor, the minority charge carriers are free electrons. These are a small number of electrons that exist due to thermal generation. - In an n-type semiconductor, the minority charge carriers are holes. These are a small number of holes that exist due to thermal generation.

Let's analyze each option and compare it with our understanding of reverse current and charge carriers: (A) holes in both p-type and n-type: This option is incorrect because, in n-type semiconductors, the minority carriers are holes, not the majority carriers. (B) free electrons in both p-type and n-type: This option is also incorrect because, in p-type semiconductors, the minority carriers are free electrons, not the majority carriers. (C) free electrons in p-type and holes in n-type: This option correctly identifies the minority carriers in each semiconductor type, which contribute to the reverse current. Hence, this is the correct answer. (D) holes in p-type and free electrons in n-type: This option is incorrect because it describes the majority carriers in each semiconductor type, which do not contribute to the reverse current when the diode is reverse-biased. The correct answer to the question "What constitutes the reverse current?" is (C) free electrons in p-type and holes in n-type.