In a metal, the drift velocity of the electrons that make up a current of a few amperes is typically
Correct answer: C. of the order of a millimetre per second
- A. close to the speed of light
- B. about 1000 m per second
- C. of the order of a millimetre per second
- D. exactly zero
Explanation
Electrons drift extremely slowly because there are so many of them, roughly 10 to the 28 per cubic metre, so a small average velocity still delivers a large current. A lamp lights instantly not because the electrons travel fast but because the electric field is established along the wire at nearly the speed of light and sets them all moving at once. Their random thermal speeds are far higher than the drift speed.
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About Steady Current
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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