What is the resistance of a 1.3 m copper wire ( = 1.7 10-8 m) that has a cross-sectional area of 8.36 10-6 m2?

The resistance of a piece of wire is given by

where
is the material resistivity
L is the length of the wire
A is its cross-sectional area

Substituting the data given by the problem, we can find the value of the resistance of the wire:

Protons have a positive charge and, collectively, give an element its atomic number.