Question

In a semiconductor, holes are present only in the ________.
A. Conduction band
B. Valence band
C. Forbidden gap
D. All of the above

Answer 1

Hint: This question is based on semiconductor, so we have to know the semiconductor and its properties to solve this question. Semiconductors are electrical instruments which are used in electronic appliances. And there are two types of semiconductors used, that is p-type and n-type semiconductors.

Complete step by step answer:
We know that semiconductors are mostly used in electronic appliances. Moreover, we have to understand more about the semiconductor to get the answer to this question.

Semiconductors are the electrical device having the electrical conductivity within the range of conductivity of a conductive substance and the materials which are insulators.
Semiconductors are of two types that are p-type and n-type semiconductors. In a p-type semiconductor, there are mostly holes present, while in the n-type semiconductor mostly electrons are present. The conductivity of any material is due to electrons.

We know that there are two kinds of bands- conduction band and valence band. In valence band, mostly holes are present while in conduction band only electrons are present.
We have to consider the materials for better understanding. Consider insulating material, in this insulating material the electrons are present in valence and there is no electron present in the conduction band. But in case of a semiconductor, at the temperature it behaves as an insulator. But, if the temperature increases, it behaves as a conductor. This happens because as the temperature of the semiconductor increases the electron present in the valence band moves to the conduction band. As a result, a hole is created in the valence band.

So, the correct answer is “Option B.

Note:
In this question, students must have knowledge of the semiconductor and its properties. Also, the types of bands are there. Semiconductor behaves as an insulator as well as a conductor, it depends on the temperature. Doping is done to increase the conductivity of the semiconductor.