Question:
When you flip a switch to turn on a light, the delay before the light turns on is determined by
When you flip a switch to turn on a light, the delay before the light turns on is determined by
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Remember that the delay in turning on the light is due to the propagation of the electric field, not the movement of electrons.
Updated On: Dec 11, 2025
- the speed of the electric field moving in the wire
- the drift speed of the electrons in the wire
- the number of electron collisions per second in the wire
- none of the above, since the light comes on instantly
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The Correct Option is A
Solution and Explanation
When the switch is flipped, the electric field propagates at nearly the speed of light, which causes the light to turn on almost instantly. The drift speed of electrons is much slower and does not determine the delay.
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