Question

Ramesh passed white light through sodium vapour lamp and observed darklines in the bright background then make assumptions for getting these dark lines on bright background.

Answer 1

Explanation:

Sodium vapor Lamp

It is kind of a light lamp that uses sodium to generate light but under ceratin specific condition i.e when sodium is excited.

There are two types of these sodium lamp, one those operate under low pressure and other in high pressure. Sodium lamps having low pressure produce yellow light whereas those sodium lights that operate under high pressure they give better light emission in term of light spectrum

Answer 2

Assumptions for observing dark lines from sodium vapor lamp:

• Sodium vapor lamp uses discharged sodium to produce light of wavelength around 589 nm.
• It uses sodium at the excited level.
• White light is a spectrum of many lights.
• When white light is passed through sodium vapor lamp, the atoms of sodium goes to the higher excited level.
• The sodium absorbs photons from white light and it is released back. Therefore, dark lines are produced.
• Thus, the dark lines are due to absorption spectrum.
• It is observed in all kinds of sodium vapor lamps.