Copper is a metal with excellent electrical conductivity due to its low resistivity and high mobility of free electrons.

Electrical conductivity is measured in Siemens per meter (S/m), which represents the ability of a material to conduct electric current.

Mercury is a metal that exhibits superconductivity below a critical temperature, allowing it to conduct electricity with zero resistance.

Conductivity and resistivity are inversely proportional, meaning that as conductivity increases, resistivity decreases, and vice versa.

In metals, conductivity generally decreases with increasing temperature due to increased scattering of electrons by lattice vibrations.

Rubber is a non-conducting material with high resistivity, making it suitable for use as an insulator in electrical applications.

Permittivity represents the ability of a material to store electrical energy when an electric field is applied.

Ceramic materials often have high permittivity, making them suitable for use in capacitors, which store electrical energy.

Permittivity and capacitance are directly proportional, meaning that as permittivity increases, capacitance also increases.

Quartz is a piezoelectric material that generates an electrical charge when subjected to mechanical stress.

Photoconductivity is the property of a material to increase its conductivity when exposed to light.

Silicon is a semiconductor material commonly used in solar cells due to its ability to absorb light and generate an electric current.

Thermoelectricity is the property of a material to generate an electric current when there is a temperature difference across it.

Chromel and Constantan are commonly used in thermocouples due to their different thermoelectric properties, allowing for accurate temperature measurement.

Piezoelectricity is the property of a material to generate an electric current when subjected to mechanical stress.