The filament of an incandescent lightbulb is a thin tungsten wire. Suppose a lightbulb h...

The filament of an incandescent lightbulb is a thin tungsten wire. Suppose a lightbulb has a resistance of at room temperature. During normal operation, the fi lament reaches a temperature of about 3000 K. (a) What is its resistance at that temperature? The temperature coefficient of resistivity for tungsten is a (b) If the bulb’s brightness depends only on the current, and a larger current gives a greater brightness, will the bulb’s brightness be greater or smaller after it has warmed up?