The filament resistance of an electric bulb is 484 Ω when it works normally. If the voltage of the filament circuit is 220 V, calculate the current passing through the filament when the bulb works normally

The filament resistance of an electric bulb is 484 Ω when it works normally. If the voltage of the filament circuit is 220 V, calculate the current passing through the filament when the bulb works normally

I = u / r = 220 V / 484 Ω = 0.455a

There is a small light bulb. When it lights normally, the resistance of the filament is 7.6 ohm and the voltage is 3.8V
There is a small light bulb. The resistance of the filament is 7.6 ohm when it normally emits light, and the voltage is 3.8V when it normally works. If we only have a 6V power supply, what is the resistance in series

3.8/6=7.6/(x+7.6) x=4.4

There is a small light bulb. When it normally emits light, the resistance of the filament is 10 Ω, and the voltage at both ends is 3,
If we only have a 9-band power supply, how large a resistor needs to be connected in series to make the bulb work normally?

First, calculate the current I = 3 pairs / 10 Ω = 0.3A when the bulb is normally emitting
The current of the series circuit is equal, and the voltage at both ends of the series resistor is 9-3 = 6
So we get r = 6 pairs / 0.3 = 20 Ω