Understanding Electrical Properties: Resistance vs. Resistivity
by Yuvi K - December 20, 2023
Understanding Electrical Properties: Resistance vs. Resistivity
When it comes to understanding electrical properties, one of the key concepts to understand is the difference between resistance (रेसिस्टेंस / resistance) and resistivity (रेसिस्टिव्हिती / resistivity). These two concepts are often confused with one another as they both relate to the flow of electrical current through a material. Knowing the difference between the two is important for electrical engineers, technicians and those looking to understand electronics in more depth.
What is Resistance?
At its core, Resistance ( रेसिस्टेंस / resistance) is the measure of the electrical current opposed to the voltage in a material. It’s measured in ohms and basically determines how difficult it is for the electric current to flow through a given material. Metals and other conductive materials usually have a low resistance, while insulators typically have a higher one.
Consider the following example to better understand resistance. Water is an excellent conductor of electricity. If you were to add a drop of salt to the water, it’s resistance would increase. This is because the salt ions in the water interfere with the electric current’s ability to flow, similar to how barriers of obstacles impede the flow of water in a river. This is an example of how resistance can impede the flow of electric current.
What is Resistivity?
Resistivity (रेसिस्टिव्हिती / resistivity) is a measure of the opposition to the flow of electric current in a given material or structure regardless of its size. It is measured in Ohm-Meters and is a property of the material itself. In other words, it measures the amount of current that can flow through a fixed piece of material regardless of its size.
To better understand resistivity’s role in electrical properties, consider the following example. Take two pieces of copper wire – one thinner than the other. Each of these two pieces will have the same resistivity regardless of their size. This means that the same amount of current will flow through them despite having different lengths or thicknesses. To conclude, resistivity is a property of a material and is independent of its size.
Resistance vs. Resistivity – the Difference
While resistance and resistivity are both measures of opposition to electric current, they have some key differences. The main difference between the two is that resistance measures the opposition to electric current with respect to its size while resistivity is the measure of opposition to electric current regardless of material size. The following table provides a more visual comparison of the two terms.
| Property | Resistance | Resistivity |
|---|---|---|
| Definition | The measure of current opposed to voltage in a material | The measure of resistance to electric current in a material |
| Units | Ohms | Ohm-Meters |
| Variability | Varies with size | Same regardless of size |
Overall, understanding the difference between resistance and resistivity can help you better understand electrical concepts and aid you in a variety of electrical designs. It’s important to note that resistance and resistivity are not the only electrical properties to understand, but they are key concepts for taking the next step in learning about electrical properties.
Conclusion
Understanding electrical properties can seem like a daunting task, but taking the time to understand concepts like resistance and resistivity can help you gain a more in-depth understanding of electronics. Whether you’re a professional electrician or a hobbyist looking to learn more, understanding resistance vs. resistivity can help you better understand the electrical world.
