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Resistance of Copper Wire

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a) What is the resistance of the wire? (see attachment for diagram and full questions)

b) If a voltage of 1mV=10^-3volts is applied across the wire, what is the current (I) and current density (J) along the wire?

c) Taking 1 electron per atom as conducting (we will justify later, why most of the Cu e-`s do not contribute), so the density of conducting e- is 1 Patomic, calculate the drift velocity of the e`s

d) Calculate the (random thermal mean squared velocity).

e) If an e- fell through a potential difference at 1mV without any collision (ballistic motion), it would gain a kinetic energy of (e)(1mV)=1^-3 eV.
Calculate N_ballistic, and N_drift/N_ballistic.

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https://brainmass.com/engineering/mechanical-engineering/resistance-copper-wire-48142

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Solution Summary

The resistance and conductivity of a wire is determined. The number of ballistic and drift collisions are also determined through the copper wire.

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See Also This Related BrainMass Solution

Copper wire length, iron wire resistance, cost of hall light

The answers are give but please provide the solutions.

Resistivity Problems:

1. How long should a copper wire 0.4mm in diameter be for it to have a resistance of 10ohms? The resistivity of copper is 1.7 x 10-8 Q-m
Answer: 74m

2. An iron wire has a resistance of 0.20ohms at 20°C and a resistance of 0.30ohms at 110°C. Find the temperature coefficient of resistance of the iron used in the wire.
Answer: 0.0056/°C

Electrical Power Problems:
1. A 75-W hall light is left on continuously. At $0.09 per kilowatt-hour, find the cost per week.
Answer: $1.13

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