Resistance and Resistivity: Understanding the distinction between resistance and resistivity is an essential component of physics education. Furthermore, the movement of free electrons is a significant distinction between resistance and resistivity. In addition, resistance is a property that prevents free electrons from flowing freely.
Resistivity, on the other hand, is a property of any substance that indicates its resistance in a specific dimension. Understanding the difference between resistance and resistivity will aid you in dealing with more advanced electrical subjects.
What is resistance?
The property of a conductor that opposes the flow of electric current is known as resistance. The voltage applied to the electric current passing through it is also known as the ratio. The resistance of a conductor is determined by its length, cross-sectional area, and the nature of the material employed in its manufacture. The resistance of a conductor is directly proportional to its length and inversely proportional to its cross-sectional area.
If an electron passes through a lot of external circuits and wires, it will meet resistance. Furthermore, resistance denotes the impediment to the charge’s flow. The journey of an electron is not straightforward. This journey is from one terminal to the next. Rather than following a straight line, the voyage follows a zigzag course.
The zigzag path is created by the electron colliding with fixed atoms within the conducting substance on numerous occasions. As a result, the electrons encounter an impediment to their movement or resistance. Furthermore, resistance prevents the charge from moving.
The pace at which the charge flows from one terminal to another is determined by the interaction of two factors. The resistance and the electric potential difference that is established between the two terminals are the most notable of these two quantities. In addition, the resistance to charge flow in an electric circuit is akin to the frictional effects that occur between a water pipe and the water.
What is resistivity?
The resistance provided by a substance per unit length for a unit cross-section is known as resistivity. Ohm. meter is the SI unit for resistivity. Temperature linearly increases resistivity. When compared to the resistivity of insulators, conductors have a low resistivity. As a result, it can be written as: conductivity of conductors, alloy resistivity, and insulator resistivity.
The resistivity of a material is a measure of its capacity to conduct electricity. The resistivity of a substance is determined by both its temperature and its electrical structure. The resistivity of most materials tends to increase as the temperature rises.
For varied materials, there is undoubtedly a wide variety of resistivity values. Other materials have lower resistivities and materials that have higher resistivities. Furthermore, the ones with lower resistivities have a low charge flow resistance. As a result, materials with low resistivities are generally superior conductors.
High resistivity materials are almost always poor conductors. Furthermore, some materials with extremely high resistivities are not considered conductors. Additionally, electrical conductivity is the inverse of resistance.
DIFFERENCE BETWEEN RESISTANCE AND RESISTIVITY
| Sl. No. | Differentiating Property | Resistance | Resistivity |
| 1 | Definition | The physical property of a substance that opposes the flow of current, i.e. electrons, is called resistance. | Resistivity is a physical property of a certain substance that has specific dimensions. |
| 2 | Proportionality | Resistance is proportional to length and temperature, but inversely proportional to the material’s cross-sectional area. | Resistivity is only proportional to the nature and temperature of the particular material. |
| 3 | Symbol | R | ρ |
| 4 | Formula | R = V/I or, R = ρ(L/A)V = Voltage, I = Current, ρ = Resistivity | ρ = (R×A)/L R = Resistance, L= Length, A = Cross-sectional area |
| 5 | SI Units | The SI unit of resistance is Ohms | The SI unit of resistivity is Ohms-meter. |
| 6 | Applications | The property of resistance is used in several places like heaters, fuses, sensors, etc. | Electrical resistivity measurement is used as a quality control test for calcareous soil. |
Resistivity and Conductivity: What Is the Connection?
Like a frictional force, resistivity is a measure of how well a material resists the flow of current, whereas conductivity is a measure of how well a conductor enables current to flow through it, like a water pipe. The larger the pipe’s diameter, the greater the water flow through it.
The inverse of conductivity is resistance, which is given by
ρ = 1/ σ
Conductivity is measured in Siemens per metre (S /m) and is indicated by the symbol ‘k or s’.
Conclusion
These are the most important resistance and resistivity distinctions to comprehend. Most tests include questions about resistivity and resistance, therefore it’s crucial to be comprehensive while making these comparisons.
