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

Question

Quizplus · Accepted Answer

The delay is determined by the speed of the electric field, which propagates at nearly the speed of light, causing the light to turn on almost instantly.

When You Flip a Switch to Turn on a Light