Difference Between Resistance and Resistivity, Major Differences

Difference Between Resistance and Resistivity : If you are preparing for the NEET Exam, you must have heard about circuits and conductivity in the physics syllabus, these two terms often raise a lot of confusion “Resistance and Resistivity”. While both relate to the flow of electricity, they play distinct roles. This blog aims to untangle the wires, providing a clear understanding of the difference between resistance and resistivity.

Difference Between Resistance and Resistivity Definition

The opposition a material offers to the flow of electric current is known as resistance. It is similar to the hurdles a sprinter faces on the track, the higher the resistance, the more difficult it is for an electric current to move through a conductor.

On the other hand, resistivity is a material's inherent quality that measures how well it can withstand the flow of electricity. Similar to the track's surface, some materials impede the current more than others by nature.

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Difference Between Resistance and Resistivity Examples

When we look at actual examples from our everyday interactions with electricity, the differences between resistivity and resistance become easier to understand.

Example of Resistance (Light bulb Filament)

Consider a light bulb. Heat and light are produced when the internal filament resists the flow of electrical current. The light bulb gets warmer and brighter as the resistance in the filament increases.

Example of Resistivity (Different Wires)

Imagine for a moment that there are two wires, one is rubber, the other is copper. Copper is a great conductor because of its low resistivity, which makes electric current flow easily through it. The rubber acts as an insulator by obstructing the flow due to its higher resistivity. When creating effective electrical systems, this distinction is essential.

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Difference Between Resistance and Resistivity

Difference Between Resistance and Resistivity Formula

Understanding the mathematical relationship between resistance ( $R$ ), resistivity ( $\rho$ ), length ( $L$ ), and cross-sectional area ( $A$ ) involves the following formula:

R = A ρ L ​

Here, $R$ is resistance, $\rho$ is resistivity, $L$ is the length of the conductor, and is its cross-sectional area. In simpler terms, this formula indicates that resistance increases with the length of the conductor and decreases with a larger cross-sectional area.

Consider a water pipe analogy, if you try to push water through a longer pipe or a narrower one, you'll encounter more resistance. Similarly, in electrical circuits, longer conductors or those with smaller cross-sectional areas impede the flow of electric current, leading to increased resistance.

It is similar to navigating an electrical landscape to know the difference between resistivity and resistance. Resistivity is a property that describes how materials naturally resist the flow of current, whereas resistance shows the obstacles that a current encounters in a particular conductor. Visualizing these concepts through everyday examples from lightbulbs to water pipes, can illuminate the intricacies of electricity's journey.

Thus, keep in mind the motion between resistance and resistivity, which affects the effectiveness of our devices and the power of our technologically advanced world, the next time you flip a switch or think about the electrical grid.