Why is argon gas used along with tungsten wire in an electric bulb?
To increase the life of the bulb
To reduce the consumption of electricity
To make the emitted light colored
To reduce the cost of the bulb
Answer is Wrong!
Answer is Right!
This question was previously asked in
UPSC CDS-1 – 2018
– High temperatures cause the tungsten metal to sublime (evaporate) from the filament.
– Evaporated tungsten atoms deposit on the cooler glass bulb wall, causing blackening.
– Sublimation thins the filament over time, eventually causing it to break.
– Inert gases like argon, krypton, or xenon, when present at pressure, impede the movement of tungsten atoms away from the filament, reducing the evaporation rate and thus prolonging the filament’s life and preventing rapid blackening of the bulb.