Hey folks! Are you having difficulty understanding the term** Resistivity? **If yes, then you are at the exact right place because after going through the content you’ll have no doubt left in** resistivity Class 10th.**

We will start with defining the term **Electrical Resistivity**. Then, we will study** Resistivity (class 10) **and will derive a formula to find the resistance of an element**.** Finally, we will discuss the variety of factors on which the resistivity of an element depends.

## Electrical Resistivity

Electrical resistivity is one of the key parameters for any material used in electrical circuits, electronic components, etc. The resistivity does not depend on the length or thickness of the material but depends on the nature of the substance and its temperature.

**SI unit = ohm-meter (Ω-m) **

**Define Resistivity Class 10th**

**Resistivity is defined as the electrical resistance offered by a conductor of unit length and unit cross-sectional area at a specific temperature.**

Resistance of any conductors is directly proportional to the length (L) of that conductor and is inversely proportional to the area of cross-sectional (A) of the conductor. The SI unit of resistivity is the same as electrical resistivity, that is, ohm-meters (Ω-m).

Let the length of the conductor be ‘L’ and ‘A’ be the cross-sectional area. Then, the expression of resistance ‘R’ of the conductor is given by:

**R∝L/AR=ρL/A**

Where ρ = resistivity of the conductor.

The general formula to determine the resistivity of any conductor is given by:

⇒ **ρ=RA/L **

Where R = Resistance

The SI unit of resistance (R) is called **ohm (Ω)**.

We know, that for a given conductor having a specified length (L) and area of intersection (A), the resistance ‘R’ is directly proportional to its resistivity ‘p’.

So, if we change the material conductor to one whose resistivity is two times, then the resistance will also become two times. And if change the material of a conductor to one whose resistivity is three times, then the resistance will become three times.

**Factors On Which Resistivity Depends:**

Resistivity is a trademark property of a component (i.e, very important).

It depends upon:

- Nature of material
- Physical conditions, like temperature

Based on the resistivity of the material, different materials can be categorized into

- Conductors – Materials that have a very low resistivity and allow the current to pass through them easily are called conductors. (Example- copper).

- Insulators – Materials that have a very high resistivity and do not allow the current to pass through them easily are called insulators. (Example- plastic).

There are some materials whose resistivity lies between conductors and insulators. They are called **alloys**.

Alloys are made up of one or more than one metal. (Example- Nichrome) Alloys have various properties dues to which they are used as heating elements in various appliances.

The resistivity of some elements are given in the table below:

Material | Resistivity (Ω m) | |
---|---|---|

Conductors | Silver | 1.60 * 10^{-8} |

Copper | 1.62 * 10^{-8} | |

Aluminium | 2.63 * 10^{-8} | |

Tungesten | 5.20 * 10^{-8} | |

Nickel | 6.84 * 10^{-8} | |

Iron | 10.0 * 10^{-8} | |

Chromium | 12.9 * 10^{-8} | |

Mercury | 94.0 * 10^{-8} | |

Manganese | 1.86 * 10^{-6} | |

Alloys | Constantan (alloy of Cu and Ni) | 49 * 10^{-6} |

Manganin (alloy of Cu , Mn and Ni) | 44 * 10^{-6} | |

Nichrome (alloy of Ni , Cr , Mn and Fe) | 100 * 10^{-6} | |

Insulators | Glass | 10^{10} to 10^{14} |

Hard rubber | 10^{13} to 10^{16} | |

Ebonite | 10^{15} to 10^{17} | |

Diamond | 10^{12} to 10^{13} | |

Paper(dry) | 10^{12} |

**Note**– Resistivity an element is the measure of the resistance of a given size of a specific material to electrical conduction.

**What is the SI unit of resistivity?**

** Ans. **ohm is SI unit of resistivity?

Related Post:- CARBON AND ITS COMPOUNDS CLASS 10th Notes – ReadAxis

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