Question

what is resistivity????????? ​

Answer 1

Hlo mate your answer

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The resiativity of a substance is equal to the resistance of a rod of that substance which is 1 m ling and i m^2 the area of its cross section.

Its unit is ohm-meter

And formula is rho = R × A / L

Answer 2

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$\boxed {\bf{De}{finition \: \div }}$

Resistivity of a material is the resistance of a wire made of that material of unit length and unit area of cross section.

$\boxed{ \bf{extra \: informations}}$

>> The Resistivity of a substance depends on the nature and temperature of a substance.

>> Resistivity doesn't depend on its length and thickness unlike resistance.

The resistance of a given conductor is directly proportional to its length, i.e

$R \: \propto \: l \: \: \: \: \: \: \: \: \: \: - - - - - > (1)$

The resistance of a given conductor is inversely proportional to its area of cross-section. i.e

$R \: \propto \: \frac{1}{A} \: \: \: \: \: \: \: \: \: \: - - - - > (2)$

So, from (1) and (2) ,we get

$R \propto \frac{1}{A}$

$R \: = \frac{p \times l}{ A} \: \: \: \: \: \: \: - - > ( \: p \: is \: a \: constant)$

$( \: resistivity) \: p = \frac{R \times A }{l}$

>> Unit of resistivity is ohm- metre.