when you flip a switch to turn on a light, the delay time before the light turns on is determined by?

Question

a.) the number of electron collissions 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.) the resistance of the material the wire is made of

Answer 1

OK, lots of wrong answers here...

Current propogates at a velocity that depends on electron pressure, which is in turn dependent on electric field. So (c) is the correct answer.

Answer 2

I would choose c) because it's the E field that gives the electrons in the bulb the energy they deliver to the radiated light.

I would argue that c) does indeed have something to do with the filament getting hot -- the electrons are accelerated by the E field and then they give up the energy they take on, heating the filament white hot.

Answer 3

Incandescent lights work by getting white hot and this takes time.

B and C have nothing to do with it getting hot, so throw them out. That leaves a or d.

Incandescent lights are weird. The resistance when off, it is different than when it is on. I think it is because the metal heats up and the resistance increases.

My best guess is a, because that's what is going to heat it up.

Answer 4

a

Answer 5

c

Answer 6

b??

Answer 7

a..........i think