Why a semiconductor is not to classify it as a resistance material?

A semiconductor is not classified as a resistance material because its electrical conductivity lies between that of a conductor and an insulator. In other words, semiconductors have a conductivity that is higher than insulators but lower than conductors. This unique property allows semiconductors to be used in electronic devices such as transistors and diodes, where they can be controlled to switch between conducting and non-conducting states. In contrast, resistance materials are typically insulators or conductors with a fixed resistance value and do not have the same ability to switch between states.

A semiconductor cannot be classified as a resistance material because its resistance is not constant. The resistance of a semiconductor varies depending on the following factors:

- Temperature: As the temperature of a semiconductor increases, its resistance decreases. This is because the higher temperature causes the atoms in the semiconductor to vibrate more, which makes it easier for electrons to move through the material.
- Light: When light shines on a semiconductor, its resistance decreases. This is because the photons in the light give the electrons in the semiconductor more energy, which makes it easier for them to move through the material.
- Impurities: The presence of impurities in a semiconductor can also affect its resistance. Impurities can either increase or decrease the resistance of the semiconductor, depending on the type of impurity.

Because the resistance of a semiconductor is not constant, it cannot be classified as a resistance material. Resistance materials are materials that have a constant resistance, regardless of the temperature, light, or impurities present.