Key Takeaways
- Resistance is a measure of how much a material opposes the flow of electric current, while resistivity is a material-specific property that quantifies the intrinsic resistance of a material.
- Resistance is represented by the symbol “R” and is measured in ohms (Ω), while resistivity is represented by the symbol “ρ” (rho) and is measured in ohm-meters (Ω·m).
- Resistance depends on the physical and geometric properties of a material, such as its length and cross-sectional area. In contrast, resistivity is an inherent property of the material and is independent of its geometry.
What is Resistance?
Resistance is a property any object or material shows that it is capable of resisting the current flow through it. It is one of the critical parameters that help determine the sum of current that can be run through an electric circuit when a given voltage is applied. The SI unit of Resistance is Ω (Ohms), represented by the capital R or ‘R.’
It is dependent on various factors, and that is – the dimensions of the object, the temperature on which it can operate, and the type of material that is used. Resistance can be measured with the help of Ohm’s Law, defined as – the resistance being equal to the applied voltage divided by the current passing.
Resistance is used to measure the resistance of a component or a circuit. Also, it helps analyze and design electrical circuits.
What is Resistivity?
Resistivity is another material property that explains the amount of flow of electric current resisted by it. Resistivity is the intrinsic property independent of the material’s dimensions, a characteristic feature. It is represented by the Greek letter ‘rho’ or ‘ρ.’ The SI unit of the term is Ωm (Ohms-meters).
It is governed by the chemical and physical properties of the material like – structure, temperature, composition, etc. Resistivity is calculated as the ratio of the strength of the electric field to the current density of the given material.
Resistivity helps to characterize the material’s conductivity. Also, it helps in selecting and comparing the materials for different physics and electrical engineering applications.
Difference Between Resistance and Resistivity
- Resistance is defined as the opposition in the flow or current in any material or an object while, on the other hand, the term Resistivity is defined as a property that defines its capability to resist the current.
- Resistance is dependent on three different factors that are – temperature, object composition, and dimensions. In contrast, Resistivity is dependent on temperature and material composition.
- The symbol representing Resistance is R, whereas, on the other hand, the symbol representing Resistivity is ρ.
- The SI unit of Resistance is Ω (Ohms). In contrast, the SI unit of Resistivity is Ωm (Ohms-meters).
- Resistance shows some properties, which are – it varies with changes in composition and temperature and is dependent on the shape and dimensions of an object. At the same time, Resistivity shows that it is independent of object size or shape but may vary with temperature change.
- Resistance is used to measure the resistance of a component or a circuit, while, Resistivity helps to characterize the material’s conductivity.
- Resistance helps analyze and design electrical circuits, whereas Resistivity helps select and compare the materials for different physics and electrical engineering applications.
Comparison Between Resistance and Resistivity
| Parameter of Comparison | Resistance | Resistivity |
|---|---|---|
| Definition | It is measured as the opposition in the flow or current in any material or an object | A property that defines its capability to resist the current |
| Dependent On | Temperature, Object Composition, Dimensions | Temperature, Material Composition |
| Represented By | R | ρ |
| SI Unit | Ω (Ohms) | Ωm (Ohms-meters) |
| Properties | Vary with changes in composition and temperature-dependent on the shape and dimensions of an object. | Independent of object size or shape but may vary with temperature change |
| Used In | It measures the resistance of a component or a circuit | It helps to characterize the conductivity of the material |
| Importance | Analyzing and designing electrical circuits | To select and compare the materials for different applications in physics and electrical engineering |
- https://iopscience.iop.org/article/10.1149/1.2404240/meta
- https://www.sciencedirect.com/science/article/abs/pii/003810989190173S
Last Updated : 31 July, 2023
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Piyush Yadav has spent the past 25 years working as a physicist in the local community. He is a physicist passionate about making science more accessible to our readers. He holds a BSc in Natural Sciences and Post Graduate Diploma in Environmental Science. You can read more about him on his bio page.
