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CURRENT ELECTRICITY — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsCURRENT ELECTRICITY2 Marks
Question
How resistivity of material depends on its temperature. Write its empirical formula.
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Answer

→ The resistivity of a material depends on temperature. Different materials do not exhibit the same dependence on temperature.
→ Over a limited range of temperatures (not too large), the resistivity of a metallic conductor is given by,
→ $\rho_{ T }= \rho _0\left[1+\alpha\left( T - T _0\right)\right]$
where,
$\begin{array}{l} 
\rho _{ T }=\text { the resistivity at temp. } T \\
\rho _0=\text { the resistivity at reference temp. } \\
\alpha=\text { temperature co-efficient of resistivity } \\
\quad \text { (unit }{ }^{\circ} C ^{-1} \text { or } K ^{-1} \text { ) } \\
T =\text { given temperature } \\
T _0=\text { reference temperature }
\end{array}$

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