Energy 6

Can you determine the length of a light bulb filament from the current flowing through it?

A 12 V tungsten filament lamp is rated at 20 W. If the filament wire has a diameter of 0.1 mm and at 0℃ has resistance 1 Ω, estimate the length of the filament.

A graph of the relative resistance vs temperature for tungsten is provided.

To get full access to the Virtual Tutor you need to or subscribe.