A copper wire has a cross sectional area A1 = 10-6m² and has a density of charge carriers of 1029 electrons/m³ . As shown in the figure, the copper wire is attached to an equal length of aluminum wire with a cross sectional area A2 = 4 x 10-8 m2, and density of charge carriers of 5 × 1028 electrons/m³. A current of 8 A flows through the copper wire. %3D Approximate resistivities of copper and aluminum are pCu = 2 x 10¬8 2.m and pAI = 3 × 10-8 2.m respectively.

An aluminum wire 1.628 mm in diameter (14-gauge) carries a current of 3.00 amps, (a) What is the absolute value of the charge density in the wire? (b) What is the drift velocity of the electrons? (c) What would be the drift velocity if the same gauge copper were used instead of aluminum? The density of copper is 8.96 g/cm3 and thedensity of aluminum is 2.70 g/cm3. The molar mass ofaluminum is 26.98 g/mol and the molar mass of copper is 63.5 g/mol. Assume each atom of metal contributes one free electron.

If the current carried by a conductor is doubled, what happens to (a) the charge carrier density, (b) the current density, (c) the electron drift velocity, and (d) the average time interval between collisions?

A 0.900-V potential difference is maintained across a 1.50-m length of tungsten wire that has a cross-sectional area of 0.600 mm2. What is the current in the wire?