Question

Resistivity of a semiconductor depends on:
A. Shape of semiconductor
B. Atomic nature of semiconductor
C. Length of semiconductor
D. Shape and atomic nature of semiconductor

Answer 1

Hint:Resistivity of a material is its own inherent property. Resistivity of the material is the ability of a material to resist the current flowing through the material which in our case is a semiconductor. The resistance of a semiconductor does not follow the same trend as that of a conductor but the resistivity of a material is the material’s own ability.

Complete answer:
 According to the Ohm’s law, “Under a definite physical condition, the current flowing through the conductor is directly proportional to the applied potential difference at its ends. Thus,
 \[
I \propto V \\
\therefore V = IR \\ \]
And here, R is the proportionality constant, which is called the resistance of the conductor. Resistance of a conductor is the ability of a conductor to resist the flow of electrons in the conductor, which is how much it stops current to get flowing in the conductor.
Resistivity of a material is the ability of the material to show resistance. Resistance in terms of resistivity is shown as follows:
\[R = \rho \dfrac{l}{A}\]
Here, R is the resistance of the conductor,\[\rho \]is the resistivity of the material, l is the length of the conductor and A is the area of the conductor.

Although all of the above formulas are for a semiconductor, we can understand that resistivity of a material is a material’s intrinsic property. It is inherited by the material and hence does not depend upon the shape or length of the material.

Hence, option B is the correct answer.

Note:Ohm’s law is only applicable on the materials which are conductors, but it is not applicable to semiconductors. The current and voltage do not have a linear relationship and instead have a parabolic relation with each other. Thus the relationship of resistance and temperature is also not linear for semiconductors.