Mistake Master
Mistake Master · AP Physics C: E&M · Unit 11 · Step-Through Animation
Slow Electrons, Instant Light
You'll learnwhy the lamp lights the instant you flip the switch, even though the electrons in the wire crawl slower than a snail.
One copper wire runs from a switch to a lamp. Flip the switch and the lamp is on immediately, yet the electrons inside the wire creep along at a third of a millimeter per second. Something else must be doing the arriving. Twelve short steps; press Next for each one.
flip the switch: the field runs, the electrons crawl
Before you start
What you're looking at
A copper wire from a switch to a lamp, drawn in profile. The dots are the mobile electrons inside it.
The question
The lamp lights the instant the switch closes. What arrived, and how fast do the electrons really move?
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