A potential difference is applied across the ends of a wire. If the potential difference is doubled, then the drift velocity of free electron will.
Correct answer: B. be doubled
- A. be quadrupled
- B. be doubled
- C. be halved
- D. remain unchanged
Explanation
Drift velocity is proportional to the electric field, and for a wire of fixed length the electric field is proportional to the applied potential difference, E = V/L. Therefore doubling the potential difference doubles the drift velocity. The common mistake is choosing quadrupled by confusing drift velocity with a quantity proportional to the square of voltage.
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Steady current is the continuous flow of charge at a constant rate through a conductor. The topic covers current, charge, potential difference, resistance, Ohm's law, resistivity and electrical power, along with series and parallel circuits, while distinguishing conventional current direction from electron motion.
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