Pls help me with my Resistivity Question in pHysics due tomorrow morning.

AI Thread Summary
The discussion revolves around several physics problems related to resistivity and resistance in wires. Key questions include determining the required length of a copper wire for a specific resistance, calculating the minimum diameter of wire to limit voltage drop, and finding potential differences across wire segments. Additionally, the impact of temperature on resistance is explored, with a focus on both copper and iron wires. Participants are encouraged to demonstrate their understanding and specify where they need assistance to facilitate effective help.
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Pls help me..thanks

Homework Statement



17. How long should a copper wire 20 mills in diameter be for it to have a resistance of 5.0Ω?

20. An electric motor draw 10 A from a 240-V source 120 ft away. What is the minimum diameter of the copper wire in mills if the voltage drop is not to exceed 2%?

22. A copper wire 1.0 mm in diameter carries a current of 12 A. Find the potential difference between two points in the wire that are 100m apart.

24. The resistance of a copper wire is 100 Ω @ 20oC. Find its resistance at 0oC and at 80oC

25. An iron wire has a resistance of 2.00 Ω at 0oC and a resistance of 2.46 Ω at 45oC. Find the temperature coefficient of resistivity of the wire
 
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