Answer:
Resistance of copper = 1.54 * 10^18 Ohms
Explanation:
Given the following data;
Length of copper, L = 3 kilometers to meters = 3 * 1000 = 3000 m
Resistivity, P = 1.7 * 10^8 Ωm
Diameter = 0.65 millimeters to meters = 0.65/1000 = 0.00065 m
[tex] Radius, r = \frac {diameter}{2} [/tex]
[tex] Radius = \frac {0.00065}{2} [/tex]
Radius = 0.000325 m
To find the resistance;
Mathematically, resistance is given by the formula;
[tex] Resistance = P \frac {L}{A} [/tex]
Where;
- P is the resistivity of the material.
- L is the length of the material.
- A is the cross-sectional area of the material.
First of all, we would find the cross-sectional area of copper.
Area of circle = πr²
Substituting into the equation, we have;
Area = 3.142 * (0.000325)²
Area = 3.142 * 1.05625 × 10^-7
Area = 3.32 × 10^-7 m²
Now, to find the resistance of copper;
[tex] Resistance = 1.7 * 10^{8} \frac {3000}{3.32 * 10^{-7}} [/tex]
[tex] Resistance = 1.7 * 10^{8} * 903614.46 [/tex]
Resistance = 1.54 * 10^18 Ohms
