Resistance of a filament lamp

Question 1

What is a current to potential difference through a filament lamp?

Answer 1

• Current is not directly porportional to the filament lamp.
• Filament gets hot, so increases the resistance.
• At high temperatures: Atoms in the filament vibrate more.
• Electrons in the current now collide more with the atoms.
• More energy is needed to push the current through the filament.

Question 2

What do we see on the graph?

Answer 2

• As p.d increases:
• Current no longer increases as much.
• NOT AN OHMIC CONDUCTOR.