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The free-electron density in a copper wire is 8.5 x 10²⁸ electrons/mº. The electric field in the wire is 0.0600 N/C and the temperature of the wire is 20.0°C. (a) What is the drift speed Va of the electrons in the wire? (b) What is the potential difference between two points in the wire that are separated by 20.0 cm?

User Fazil
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The drift speed and potential difference in a conductor can be calculated using free electron density, current, cross-sectional area of the wire, electric field, and the dimensions of the wire in physics.

Drift speed (Va) and potential difference are key concepts in the study of electricity in physics. When calculating the drift speed of electrons in a conductor, we use the density of free electrons, the charge of an electron, and the current through the conductor. For copper, with a free-electron density of 8.5 x 10²28 electrons/m³, and assuming one free electron per copper atom, we can determine the number of free electrons using the atomic mass of copper, the density of copper, and Avogadro's number. The drift speed is then calculated using the formula I = nqAvd, where I is the current, n the number density of electrons, q the charge of an electron, A the cross-sectional area of the wire, and vd the drift speed.

For the potential difference, Ohm's law (V = IR, where V is the potential difference, I the current, and R the resistance) is used in conjunction with the length of the conductor and its resistivity. The resistivity can be determined using the known resistivity of copper and the dimensions of the wire. By multiplying the electric field by the distance between the two points in the wire, we can find the potential difference.

User Obaylis
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