Answer:

Electric bulbs, also known as incandescent lamps, are filled with inert gases to prevent the filament from oxidizing and burning out quickly. The inert gases inside the bulb do not react with the hot filament and help prolong the life of the bulb. The most commonly used inert gases in electric bulbs are argon and nitrogen.

The gases filled in electric bulbs:

- Option (a): Helium and Neon: Helium is not typically used in electric bulbs because it is an expensive gas and has a low atomic weight, which can cause it to leak through the glass envelope of the bulb. Neon, on the other hand, is often used in neon signs and fluorescent lamps, but not in electric bulbs.

- Option (b): Neon and Argon: This option is correct. Argon is the most commonly used gas in electric bulbs. It is an inert gas that does not react with the filament or the glass envelope. Neon is also sometimes used in combination with argon to produce a colored light.

- Option (c): Argon and Hydrogen: Hydrogen is a highly flammable gas and is not suitable for use in electric bulbs. It can react with the hot filament and cause a fire hazard. Therefore, argon is the preferred choice for inert gas filling in electric bulbs.

- Option (d): Argon and Nitrogen: This option is correct. Argon and nitrogen are both inert gases and can be used in electric bulbs. Nitrogen is less commonly used compared to argon, but it can still provide the desired inert atmosphere inside the bulb.

In summary: The correct gases that are commonly filled in electric bulbs are argon and sometimes neon (in combination with argon). Helium and hydrogen are not commonly used due to their properties. Nitrogen is less commonly used but can also be used as an inert gas filling.

Argon and nitrogen