Power out put of a light bulb

When the bulb is hooked up to a power supply, an electric current flows from one contact to the other, through the wires and the string. As the electrons move along through the string, they are continuously bumping into the atoms that make up the string. The energy of each collision vibrates the atom. A thinner conductor heats up more easily than a thicker conductor because it is more resistant to the movement of electrons.

The filament in a light bulb is made of a long, thin length of tungsten metal. In a 60-watt bulb, the tungsten filament is about 2 meters long but only about one hundredth of an inch thick.

Tungsten is used in nearly all bright light bulbs because it is a perfect filament material

Resistance and Power output of a light bulb

In this experiment we set up a circuit by connecting a light bulb to a power output via a voltmeter and an ammeter. We then measured the voltage and the amps varied with the potential difference.

When we had found the volts and amps we were able to work out resistance and the power output. We then drew two graphs, measuring the resistance varied with the potential difference and the power output varied with the potential difference.