Define the term electrical conductivity of a metallic wire. Write its SI unit.

Explanation

Detintiton and SI unit of conductivity
The conductivity of a material equals the reciprocal of the ace of its wire of unit length and unit area of cross section
[Alternatively : The conductivity (`sigma ) ` of a material is the reciprocal of its resitivity `(rho ) ` ]
` ( sigma =(I)/(rho) ) `
Its SI unit is