Resistance and resistivity are related concepts that describe how much an object or a material opposes the flow of electric current.
1.Resistance is a property that depends on the length, cross-sectional area, and nature of the material, while resistivity is a property that depends only on the nature and temperature of the material.
2.Resistance is measured in ohms (Ω) and resistivity is measured in ohm-meters (Ωm).
The formula for resistance is
R = V/I or
R = ρ L/A
where V is voltage,
I is current,
ρ is resistivity,
L is length,
A is cross-sectional area.
The formula for resistivity is
ρ = (R×A)/L.
(6) Difference between Resistance and Resistivity –
| Difference | Resistance | Resistivity |
|---|---|---|
| Definition | The property that opposes the flow of electric current | The attribute of the material that defines the resistance per unit length and cross-sectional area |
| Symbol | R | ρ |
| SI Unit | Ohm (Ω) | Ohm-meter (Ωm) |
| Formula | R = V/I or R = ρ(L/A) | ρ = (R×A)/L |
| Dependence | Length, cross-sectional area, nature and temperature of material | Nature and temperature of material |
| Applications | Heaters, fuses, sensors, etc. | Quality control test for calcareous soil²¹³ |
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