15. A 2.50-m cylindrical rod of diameter 0.500 cm is connected to a power supply that maintains a constant potential difference of 18.0 V across its ends, while an ammeter measures the current through it. You observe that at room temperature (20.0°C) the ammeter reads 18.8 A, while at 92.0°C it reads 17.1 A. You can ignore any thermal expansion of the rod. Find the resistivity in μm at 20.0°C. Round-off to the nearest hundredth.

15. A 2.50-m cylindrical rod of diameter 0.500 cm is connected to a power supply that maintains a constant potential difference of 18.0 V across its ends, while an ammeter measures the current through it. You observe that at room temperature (20.0°C) the ammeter reads 18.8 A, while at 92.0°C it reads 17.1 A. You can ignore any thermal expansion of the rod. Find the resistivity in μm at 20.0°C. Round-off to the nearest hundredth.

Physics for Scientists and Engineers, Technology Update (No access codes included)

9th Edition

ISBN:9781305116399

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter27: Current And Resistance

Section: Chapter Questions

Problem 27.75AP: Review. When a straight wire is warmed, its resistance is given by R = R0,[1 + a(T T0)] according...

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