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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