Why does light bulb appear lit?

[convo_king89]

This is a bit different question than my usual sexual questions. If ac voltage is always going on and off equally like 50% on and 50% why is it bulbs looks like it’s on not off. I’m thinking lenz law, but I am not sure.

[DCooper]

It's true that the current flowing through the filament is cycling continuously. But it takes a lot longer than 1/120th of a second for it to heat up and cool off. Thus it continuously glows.

[convo_king89]

Heat up and cool down meaning light going off? I just figured lenz law would use the voltage stored to keep it for a tad longer

[DCooper]

Sort of. The light is given off due to the filament's temperature, which in turn is a function of the heat in (current times resistance) and heat out (radiated and convected to the environmen). At least in this example of an incandescent bulb, it doesn't flicker because it cannot heat up and cool down as fast as the current flow cycles between peak and neutral.

[convo_king89]

Oh that’s right I forgot of the incandescent bulb, it basically works like an electric stove.

[DCooper]

Lenz's law doesn't really have a significant effect because a light bulb filament isn't much of a coil for a collapsing field to induce a counter emf in.

Now the secondary side of a stepdown transformer is the opposite end of the spectrum. Pinch a AA battery between that coil's ends, and then let the AA drop out while still touching the coil wires, and you will definitely feel the counter emf induced by the collapsing magnetic field across the conductors.

[convo_king89]

Well I was thinking the
Copper wires, I know it was a long shot but I was drawing and blank.

[DCooper]

It should actually induce a current, but its effect on a single conductor is too small to be significant.

[convo_king89]

Exactly

[Breebabe15]

I think its because of retina burn with eyes if we are looking at the blub plus doesn't the wire in the globe heat up so it would be the glowing heat of the metal

[OddBeMe]

Alternating current

[convo_king89]

You didn’t read the details

[OddBeMe]

didn't think you knew what AC meant.

[Jamie05rhs]

@Wiredone