Resistivity of a wire is a measure of the resistance a wire offers to the flow of electric current. It is a material property and is dependent on the type of material, cross-sectional area, and length of the wire.
Resistivity of a wire is calculated by dividing the resistance of the wire by its cross-sectional area and length. The formula for resistivity is ρ = R x A / L, where ρ is the resistivity, R is the resistance, A is the cross-sectional area and L is the length of the wire.
The unit of resistivity is ohm-meter (Ωm) in the SI (International System of Units). In some cases, the unit of ohm-centimeter (Ωcm) is also used for resistivity.
Temperature has a significant effect on the resistivity of a wire. As the temperature increases, the resistivity of the wire also increases. This is because the increase in temperature causes the atoms of the wire to vibrate more, leading to more collisions with the electrons, which increases the resistance and hence the resistivity.
The resistivity of a wire depends on various factors such as the type of material, temperature, cross-sectional area, and length of the wire. The type of material and temperature have the most significant impact on resistivity, while the cross-sectional area and length also play a role in determining the resistivity of a wire.