Uploaded May 2021 | Updated September 2026, 2 weeks ago
This video investigates the resistance of a filament lamp: looking at the filament lamp itself and also shape of the current / potential difference graph and discovering what this means.
First of all a recap is taken looking at a linear resistor to understand what an Ohmic component is. The current and voltage are measured to establish the relationship between current and voltage and see that there is a linear relationship for this type of component. The plot of current and voltage gives a straight line
Incandescent or filament lamps consist of a very fine coiled wire coil or filament within the glass bulb. When current passes through this filament, it heats up, becoming white hot and giving out light.
These filament lights are very inefficient converting around 5% of the energy that enters them into light. LEDs are now the preferred form of lamp for many situations.
There is an experiment to measure the resistance of the filament lamp using a voltmeter and an ammeter so that the plot of the current and voltage can be seen. This is not a straight line and this means that the resistance of the filament lamp changes with the potential applied.
As the resistance of the filament lamp changes with voltage, it is said to be non-Ohmic.
Read more about the resistance of a filament lamp here: electronics-notes.com/articles/basic_concepts/resistance/why-is-filament-incandescent-lamp-nonohmic.php
Associated website: electronics-notes.com
Don’t forget to subscribe to the ElectronicsNotes YouTube channel: youtube.com/channel/ElectronicsNotes
This video investigates the resistance of a filament lamp: looking at the filament lamp itself and also shape of the current / potential difference graph and discovering what this means.
First of all a recap is taken looking at a linear resistor to understand what an Ohmic component is. The current and voltage are measured to establish the relationship between current and voltage and see that there is a linear relationship for this type of component. The plot of current and voltage gives a straight line
Incandescent or filament lamps consist of a very fine coiled wire coil or filament within the glass bulb. When current passes through this filament, it heats up, becoming white hot and giving out light.
These filament lights are very inefficient converting around 5% of the energy that enters them into light. LEDs are now the preferred form of lamp for many situations.
There is an experiment to measure the resistance of the filament lamp using a voltmeter and an ammeter so that the plot of the current and voltage can be seen. This is not a straight line and this means that the resistance of the filament lamp changes with the potential applied.
As the resistance of the filament lamp changes with voltage, it is said to be non-Ohmic.
Read more about the resistance of a filament lamp here: electronics-notes.com/articles/basic_concepts/resistance/why-is-filament-incandescent-lamp-nonohmic.php
Associated website: electronics-notes.com
Don’t forget to subscribe to the ElectronicsNotes YouTube channel: youtube.com/channel/ElectronicsNotes
