Question

Which type of vapour is stored in Mercury lamp ?

• A. Mercury vapour
• B. Hydrogen vapour
• C. Xe
• D. Ozone

Hint:

Discharge Lamps. The name usually indicates the primary gas or vapor used for light production via electrical discharge, e.g., Mercury lamp (mercury vapor), Sodium lamp (sodium vapor), Xenon lamp (xenon gas).

Answer 1

The Correct Option is A

Mercury-vapor lamps are a type of gas-discharge lamp that produces light by passing an electric arc through vaporized mercury
The electric discharge excites the mercury atoms, causing them to emit photons, primarily in the ultraviolet (UV) range, along with some visible light
Often, the inner surface of the bulb is coated with phosphors that absorb the UV light and re-emit it as visible light, improving efficiency and color rendering (as in fluorescent lamps, which are low-pressure mercury lamps)
High-pressure mercury lamps emit more visible light directly
In either case, the primary active medium is mercury vapor
Other gases like argon may be present as starter gases, but mercury vapor is essential for the light production mechanism