Questions

Resistivity :

Resistivity is a measure of the resistance to the flow of electrons. 

Conductivity :

Conductivity is just the inverse of resistivity, σ = 1/ρ, where σ is conductivity and ρ is resistivity.

Example:

Think of a pipe and water, the bigger the pipe, the easier water can flow and thus the lower the resistance. 

In all the given options, molecules are containing nonpolar covalent bonds.

Cost Estimating - Developing an approximation of the costs of the resources needed to complete  project activities.

Cost Budgeting - Aggregating the estimated costs of individual activities or work packages to establish a cost baseline

Cost Control - Influencing the factors that create cost variances and controlling changes to the project budget.

The study of flags is called Vexillology and the art of flag design is called as Vexillography. The man who studies flags is called as Vexillologist.