Question
Tue February 05, 2013 By: Michelle
 

Though the drift speed of an electron is responsible for current in conductor is very small,lights in a room turns on immediately after the switch is on. why is it so?

Expert Reply
Wed February 06, 2013
The electrons that light the bulb immediately after the switch is turned to on are the electrons that are present in the filament itself. As the switch is flipped, all mobile electrons everywhere begin marching; and it is the mobile electrons present in the filament whose motion are immediately responsible for the lighting of its bulb. As those electrons leave the filament, new electrons enter and become the ones that are responsible for lighting the bulb.
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