Resistivity of Metals, Semiconductors, and Insulators

Current flowing through a conductor is directly proportional to the potential difference.

Resistance is determined by comparing the slopes of V-I graphs of different materials.

Conductance is the reciprocal of resistance. Its unit is siemens (S) or mho.

<p>The material, length, and cross-sectional area of the conductor.</p> Signup and view all the answers

<p>Resistivity is the property that relates resistance to the material. Its unit is ohm-meter (Ωm).</p> Signup and view all the answers

<p>The resistivity of the material remains unchanged.</p> Signup and view all the answers

<p>Resistance offered by the electrolytes to the flow of current through it.</p> Signup and view all the answers

<p>V = ε – Ir</p> Signup and view all the answers

<p>Emf is the potential difference in an open circuit, while terminal voltage is in a closed circuit.</p> Signup and view all the answers

<p>Their resistivity does not vary considerably with temperature.</p> Signup and view all the answers

<p>It decreases.</p> Signup and view all the answers

<p>14Ω</p> Signup and view all the answers

<p>Conductivity is the reciprocal of resistivity.</p> Signup and view all the answers

<p>$\mathbf{j} = \sigma \mathbf{E}$</p> Signup and view all the answers

<p>Some materials and devices used in electric circuits do not obey Ohm’s law and are called Non-Ohmic conductors. V-I graphs of non-ohmic conductors are not linear.</p> Signup and view all the answers

<p>Ohmic conductors obey Ohm’s law, have a linear Voltage-Current graph, and include metals like Nichrome. Non-ohmic conductors do not obey Ohm’s law, have non-linear V-I graphs, and include materials like semiconductors, diodes, and transistors.</p> Signup and view all the answers

<p>$\rho_T = \rho_0 [1 + \alpha(T - T_0)]$, where $\alpha = (T - T_0)\frac{\rho_0}{\rho}$ is the temperature co-efficient of resistivity. The unit of $\alpha$ is $K^{-1}$ and its dimension is $[Temperature]^{-1}$.</p> Signup and view all the answers

<p>The resistivity of metals increases with temperature. This increase is described by the temperature co-efficient of resistivity, $\alpha$, which is positive for metals.</p> Signup and view all the answers