Which of the following electrical quantities is represented by ‘σ(sigma)’?

The correct answer is option 2):(Conductivity )

Concept:

Conductivity:

• Conductivity is the measure of the ease at which an electric charge or heat can pass through a material
• The material which has high conductivity is called conductor and which has very low conductivity is called non-conductor
• Metal has high conductivity and non-metal has very low conductivity
• Electrical conductivity is also known as specific conductance
• It is denoted by the symbol σ and has SI units of Siemens per meter (S/m) or Ω^-1m^-1 or mho/m

Additional Information

• Conductance is an expression of the ease with which electric current flows through materials like metals and nonmetals. In equations, an uppercase letter G symbolizes conductance. The standard unit of conductance is siemens (S), formerly known as mho.
• Resistance is a measure of the opposition to current flow in an electrical circuit. Resistance is measured in ohms, symbolized by the Greek letter omega (Ω). 
• Electrical resistivity is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows electric current. Resistivity is commonly represented by the Greek letter ρ. The SI unit of electrical resistivity is the ohm-meter.