How Does Resistivity Affect Copper Wire Resistance and Current Flow?

AI Thread Summary
The discussion focuses on calculating the resistance of 12-gauge copper wire and the current flow when a voltage is applied. The resistance formula used is R=ρ(L/A), with the area calculated as A=∏r², resulting in an area of 3.33E-6 m². The resistance was calculated to be 0.0587 ohms, but the user encountered an error due to significant figures. The importance of precision in calculations, particularly with significant figures, is emphasized in the context of electrical resistance and current flow.
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12-gauge copper wire has a radius of 1.03×10−3 m. (a) What is the resistance of 11.5 m of this wire at 20°C. (b) How much current will pass through the wire if a potential difference of 9.00 V is applied across it?
The resistivity for copper is 1.7E-8 ohm meters
For part a:
The equation is R=ρ(L/A) and A=∏r2.
I solved for Area and got 3.33E-6 m2.
Then I did R=1.7E-8(11.5/3.33E-6)
R=.0587 ohms.

However, when I plug this into the system it says it's wrong. What did I do incorrectly? I double-checked my multiplication and everything.
 
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Never mind, it was sig figs
 

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