Question

Calculate the resistance of 100 m long copper wire whose diameter is 1mm. The resistivity of copper is 1.6 × 10 ^ -8 ... please tell me I will mark you as brainlist​

Answer 1

Answer:

First you have to figure out the number of atoms of copper in that volume of copper wire. Then you will multiply the number of copper atoms in that volume with the number of electrons per copper atom. So the volume of the copper wire will be : (pr^2)(L). Then you will need the density of copper at room temperature and pressure and multiply the density with the volume above to get the mass of copper in that volume of copper. Once you get the mass of copper, you must divide that by the molar mass of copper which is 63.54 gram per mole of copper. That will give you the number of moles of copper in that volume of copper. Then you have to multiply the number of moles of copper by Avogadro’s number which is 6.02•10^23, which will give you the number of atoms of copper in that volume. Then now you will multiply the number of atoms with copper’s atomic number(same as number of electrons per atom) to get the total number of electrons in that volume. So let me state in mathematical terms: {(pr^2)(L)(d)/M}•(A)•(E) = electrons(in that volume). Here p is pi, r is the radius of the copper wire, which would be half the diameter(0.25 cm), L is the length of the copper wire(1cm), d is the density of copper(8.92g/cm^3), M is the molar mass of copper(63.54 gram per mole), A is Avogadro's number(6.02 times 10^23 atoms per mole), and E is the number of electrons per copper atom which is 29, same as the atomic number of copper. Once calculated the number of electrons is 4.812 times 10^23 electrons, or four hundred eighty one thousand and two hundred billion billion electrons, in that volume of copper wire. Kaiser T, MD(Life long physics, math, cosmology, and science proponent).