Chapter 17 - Electric Current and Resistance - Learning Path Questions and Exercises - Conceptual Questions - Page 618: 6

It is the electrical signal that turns the lamp on at nearly the speed of light, not the course of individual electrons moving through the circuit. The circuit already contains plenty of electrons that move through the wire that leads to the light switch. When we turn on the light, it is propagation of the electrical signal that causes the light to turn on almost instantaneously.

It is the electrical signal that turns the lamp on at nearly the speed of light, not the course of individual electrons moving through the circuit. The circuit already contains plenty of electrons that move through the wire that leads to the light switch. When we turn on the light, it is propagation of the electrical signal that causes the light to turn on almost instantaneously.