Taking the resistivity of platinoid as 3.3 × 〖10〗^(-7) Ω m, find the resistance of 7.0 of platinoid wire of average diameter 0.14 cm.
7.0 what? inches, feet, miles?
more likely, something metric ...
One never knows.
To find the resistance of the platinoid wire, you can use the formula: R = ρ * (L/A)
Where:
R = Resistance
ρ = Resistivity
L = Length of the wire
A = Cross-sectional area of the wire
In this case, the resistivity of platinoid (ρ) is given as 3.3 × 〖10〗^(-7) Ωm.
To find the length of the wire (L), you need more information. If the length is not provided, you won't be able to calculate the resistance accurately. Let's assume a length of 7.0 meters (as mentioned in your question), and we'll proceed with that assumption.
The average diameter of the wire is given as 0.14 cm. The first step is to convert the diameter to the radius by dividing it by 2.
Radius (r) = diameter / 2 = 0.14 cm / 2 = 0.07 cm
Next, let's convert the radius from centimeters to meters by dividing it by 100 (since there are 100 centimeters in a meter).
Radius (r) = 0.07 cm / 100 = 0.0007 meters
Now, we can calculate the cross-sectional area (A) of the wire using the formula: A = π * r^2
Cross-sectional area (A) = π * (0.0007 meters)^2 ≈ 0.00154 square meters (rounded to 5 decimal places)
Finally, substituting the given values into the resistance formula, we get:
R = (3.3 × 〖10〗^(-7) Ωm) * (7.0 meters) / 0.00154 square meters
R ≈ 2.86 Ω (rounded to 2 decimal places)
Therefore, the resistance of the 7.0 meters of platinoid wire with an average diameter of 0.14 cm is approximately 2.86 Ω.