Inactive Nitrogen and Argon gases are usually used in electric bulbs in order to

Inactive gases like nitrogen and argon are used in electric bulbs primarily to increase the life of the filament. In a vacuum, the tungsten filament evaporates rapidly at high temperatures, leading to bulb blackening and eventual filament failure [1]. Filling the bulb with an inert gas creates pressure that suppresses this evaporation process [1]. Furthermore, these gases provide a non-oxidizing environment, preventing the filament from burning up in the presence of oxygen. While argon is the most common filler due to its abundance and low cost, nitrogen is often added to minimize the risk of electrical arcing, which could otherwise destroy the lamp [1]. Although these gases can slightly reduce efficiency by conducting heat away from the filament, their role in preventing filament deterioration and extending the bulb's operational lifespan is critical [1].

Sources

1. [1] https://www.sciencedirect.com/topics/engineering/filament-lamp