Loading…
Loading…
GCSE Physics · key term
A thin wire inside a filament lamp that becomes hot enough to emit light when current passes through it.
Used by AQA
Specification 4.2.1.4 · Paper 1
Revise: Sensing Components: Lamps, Diodes, Thermistors and LDRsA filament lamp contains a very thin metal filament. When current passes through it, electrical energy is transferred to the filament's thermal energy store, so its temperature rises. The moving electrons interact with the vibrating ions in the metal lattice.
For a filament lamp, do not say that the current falls as the potential difference rises. The current rises, but less rapidly because the hot filament's resistance increases.
Keep the relationships distinct: a hotter thermistor has lower resistance; a hotter filament lamp has higher resistance; an LDR in brighter light has lower resistance.
Create a free account to read GCSE Physics revision notes for your exam board and track your progress.