What is difference between resistance and resistivity?
What is difference between resistance and resistivity?
Resistance:
Resistance is a property of a material that opposes the flow of electric current through it. It is a measure of how difficult it is for the electric charges to move through a conductor. Resistance is represented by the symbol "R" and is measured in ohms (Ω).
Resistivity:
Resistivity, on the other hand, is an intrinsic property of a material that describes how strongly it resists the flow of electric current. It is denoted by the symbol "ρ" (rho) and is measured in ohm-meters (Ω·m). Resistivity is specific to each material and depends on factors like temperature and impurities in the material.
Differences:
1. Definition and Symbol:
- Resistance is a property that opposes the flow of electric current and is represented by the symbol "R".
- Resistivity is an intrinsic property of a material and represents its resistance to the flow of electric current. It is denoted by the symbol "ρ" (rho).
2. Nature:
- Resistance is a macroscopic property and depends on both the material and the dimensions of the conductor.
- Resistivity is a microscopic property and depends solely on the material.
3. Calculation:
- Resistance can be calculated using Ohm's law: R = V/I, where V is the voltage across the conductor and I is the current flowing through it.
- Resistivity is calculated using the formula: R = (ρ * L) / A, where R is the resistance, ρ is the resistivity, L is the length of the conductor, and A is its cross-sectional area.
4. Temperature Dependence:
- Resistance generally increases with an increase in temperature for most conductors.
- Resistivity also changes with temperature, but the relationship can be more complex and depends on the material.
5. Material Dependency:
- Resistance is affected by the dimensions of the conductor and the specific material.
- Resistivity is an intrinsic property of the material and remains constant regardless of the dimensions of the conductor.
6. Unit of Measurement:
- Resistance is measured in ohms (Ω).
- Resistivity is measured in ohm-meters (Ω·m).
In summary, resistance is a property that opposes the flow of electric current through a conductor, while resistivity is an intrinsic property of a material that describes its resistance to the flow of current. Resistance depends on both the material and the dimensions of the conductor, while resistivity is solely dependent on the material. Resistance is measured in ohms, while resistivity is measured in ohm-meters.
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