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jimbo71
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What's the difference between resistivity and resistance?
Resistivity is a property of a material that measures how well it can resist the flow of electricity, while resistance is a measure of how much a specific object or material impedes the flow of electricity. In other words, resistivity is an intrinsic property of a material, while resistance is a measurable quantity of a specific object.
Resistivity is directly proportional to temperature. This means that as the temperature of a material increases, its resistivity also increases. This relationship is described by the temperature coefficient of resistivity, which is a constant specific to each material.
The unit of resistivity is ohm-meter (Ω·m) and the unit of resistance is ohm (Ω). Both units are derived from the fundamental SI unit of electric current, ampere (A).
The longer the length of a material, the higher its resistance will be, as there is more material for the electrons to travel through. On the other hand, the larger the cross-sectional area, the lower the resistance will be, as there is more space for the electrons to flow through. This relationship is described by the formula R = ρL/A, where R is resistance, ρ is resistivity, L is length, and A is cross-sectional area.
The resistivity of a material can be affected by temperature, impurities, and the material's crystal structure. For example, increasing temperature can increase resistivity, while adding impurities can decrease resistivity. Additionally, different materials have different crystal structures, which can affect how easily electrons can flow through them and thus their resistivity.