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A steady current of 5 A flows through a cylindrical copper wire of resistivity 1.7 * 10⁻⁸ ohm*m and cross-sectional radius 5 mm. If the charge carriers drift with a speed of 1.1 * 10⁻³ m/s, determine their mobility.

1. 1.3 m²/Vs
2. 1.5 m²/Vs
3. 1.8 m²/Vs
4. 1.0 m²/Vs

Correct answer: 1.0 m²/Vs

Solution

The mobility equals the drift velocity divided by the internal field E = rho*J, giving about 1.0 m²/Vs.

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