Copper contains 8.4* 10²⁸ free electrons/m³. A copper wire of cross-sectional area 7.4 *10^-⁷ m² carries a current of 1 A. The electron drift speed is approximately: A) 3 * 10⁸ m/s B) 10³ m/s C) 1 m/s D) 10^-⁴ m/s E) 10^-²³ m/s

Question

Quizplus · Accepted Answer

The electron drift speed can be calculated using the formula $ v_d = \frac{I}{nAe} $, where $ I $ is the current, $ n $ is the number of free electrons per unit volume, $ A $ is the cross-sectional area, and $ e $ is the charge of an electron. Substituting the given values, the drift speed is approximately $ 10^{-4} $ m/s.

Copper Contains 8