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Electrical resistivity (also called volume resistivity or specific electrical resistance) is a fundamental specific property of a material that measures its electrical resistance or how strongly it resists electric current. A low resistivity indicates a material that readily allows electric current.
Conductivity is represented by \( \sigma \) and is measured in Siemens (\(1/Ωm\)). Since conductivity is the measure of how easily electricity flows, electrical resistivity measures how much a material resists the flow of electricity.
Differentiate between resistance and resistivity; Define the term conductivity; Describe the electrical component known as a resistor; State the relationship between resistance of a resistor and its length, cross-sectional area, and resistivity; State the relationship between resistivity and temperature
For example, the resistivity of a good conductor such as copper is on the order of 1.72 x 10 -8 ohm metre (or 17.2 nΩm), whereas the resistivity of a poor conductor (insulator) such as air can be well over 1.5 x 10 14 or 150 trillion Ωm.
Differentiate between resistance and resistivity; Define the term conductivity; Describe the electrical component known as a resistor; State the relationship between resistance of a resistor and its length, cross-sectional area, and resistivity; State the relationship between resistivity and temperature
Resistivity is a fundamental material property (like density or melting point), while the total resistance (R) depends on the material, the geometry, and the temperature. The dependence on geometry (really, a volume dependence: cross-sectional area (A) and length(L)) can be quantified: = ρ.
16 Αυγ 2021 · The resistance \(R\) of a cylinder of length \(L\) and cross-sectional area \(A\) is \(R = \frac{\rho L}{A}\), where \(\rho\) is the resistivity of the material. Values of \(\rho\) in the Table show that materials fall into three groups—conductors, semiconductors, and insulators.
