When you flip a switch to turn on a light,the delay before the light turns on is determined by:
A)the number of electron collisions per second in the wire.
B)the drift speed of the electrons in the wire.
C)the speed of the electric field moving in the wire.
D)none of these,since the light comes on instantly.

Question

Quizplus · Accepted Answer

The delay before the light turns on is determined by the speed of the electric field moving in the wire, which propagates at a significant fraction of the speed of light. This is much faster than the drift speed of electrons, making the response nearly instantaneous to human perception.

When You Flip a Switch to Turn on a Light,the