Electrical Properties of Material

  • To understand basic electrical property of the engineering materials.

  • Define electrical properties of a material such as electrical conductivity,semi- and super-conductivity, resistivity and their importance in calculation of resistance.

  • To understand the energy-band model for electrical conduction in materials.

  • Resistivity Electrical resistivity (also known as resistivity, specific electrical resistance, or volume resistivity) is an intrinsic property that quantifies how strongly a given material opposes the flow of electric current.

  • Electrical conductivity Electrical conductivity or specific conductance is the reciprocal of electrical resistivity, and measures a material’s ability to conduct an electric current.

  • An isotropic material has identical values of a property in all directions. An opposite behaviour will be referred as anisotropic behaviour. Wood is an example of anisotropic material.

  • Allotropy is the property to exist in two or more different forms. Graphite and diamonds are allotropes of Carbon. Pure iron can exist in three different forms alpha iron, gamma from and delta iron depending upon the temperature.

Solved Example:

50-2-01

What physical property of a material refers to the highest potential difference (voltage) that an insulating material of given thickness can withstand for a specified time without occurrence of electrical breakdown through its bulk?

Correct Answer: C

Solved Example:

50-2-02

With the rise of temperature, the conductivity of a semi-conductor: (Airforce Group X Jul 2021 Shift I)

Correct Answer: C