Aluminum wire has 0.25mm radius and length of 75 m . If resistance of ...
Calculation of resistivity of aluminum wire
Given Data:
- Radius of aluminum wire (r) = 0.25mm
- Length of aluminum wire (l) = 75m
- Resistance of aluminum wire (R) = 10 ohm
Formula:
The resistance of a wire is given by the formula:
R = (ρ * l) / A
where ρ is the resistivity of the material, l is the length of the wire, and A is the cross-sectional area of the wire.
The cross-sectional area of a wire is given by the formula:
A = π * r^2
where r is the radius of the wire.
Solution:
First, we need to calculate the cross-sectional area of the aluminum wire:
A = π * r^2 = 3.14 * (0.25mm)^2 = 0.19635 mm^2
Now, we can use the resistance formula to calculate the resistivity of aluminum:
R = (ρ * l) / A
ρ = (R * A) / l = (10 ohm * 0.19635 mm^2) / 75m = 26.28 x 10^-9 ohm m
Answer:
The resistivity of aluminum wire is 26.28 x 10^-9 ohm m.