Question

Resistance of bulb remain constant during opeartion?

Answer 1

For a given resistance, V = iR, so the bulb's resistance (when it has 120 volts across it) is 120/(1/3), or 360 ohms. ... The resistance of a light bulb filament changes with temperature, but if we ignore this, we can at least roughly estimate the current flow and power dissipation in the series circuit