See the attached file.
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.
The resistance and conductivity of a wire is determined. The number of ballistic and drift collisions are also determined through the copper wire.
Copper wire length, iron wire resistance, cost of hall light
The answers are give but please provide the solutions.
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
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.
Electrical Power Problems:
1. A 75-W hall light is left on continuously. At $0.09 per kilowatt-hour, find the cost per week.