0
The light in Sodium Vapour lamp is from an atomic emission process whereas in Mercury Vapour Lamp it is, finally, from fluorescence emission. The mechanism of light emission in a sodium vapour lamp is simple and straight-forward. The filaments of the lamp sputter fast moving electrons, which hit the sodium atoms(vapour) causing the valence electrons of the sodium atoms to excite to higher energy levels and the electrons thus excited relax by emiting the characteristic monochromatic bright yellow light(589nm). The mechanism in mercury vapour lamp is more involved and sequential. The sputtered electrons from the filaments, after having been accelerated by high voltage, hit the mercury atoms. Here also, the excited electrons of mercury atomsrelax by emitting characteristic but ultravilot(254nm,invisible) light. The photons of this ultravilot light fall on the fluorescent layer on the inner walls of the tube and excite the molecular bonds of the fluorescent material to various electronic and vibrational energy states. Hence, the light from the mercury vapour lamp is white. The basic difference between the two is, the former works by electric discharge (passage of electricity through sodium vapours at high/low pressure) while the latter works through the combined effect of electric discharge through mercury vapours and fluorescence from phosphors (luminescent materials). Although sodium vapour lamps produce much higher light output (about 90 lumens/watt) they cannot be used in lighting applications where colour-rendering property is very crucial. This is because most of the light emitted from a sodium vapour lamp is concentrated in the yellow part of the visible spectrum (around 580-590 nm) On the other hand, a mercury vapour lamp is quite suitable for lighting applications. This is because, the mercury vapour lamp can feed almost the entire visible region (380-780 nm) of the human visual system. Conventional fluorescent lamps can also be called as low-pressure mercury discharge lamps. In this system, when electric discharge strikes mercury vapours held at low pressure ( a few mm of mercury) it produces a lot of ultravilot radiation dominantly at 254 nm inside the column of the discharge tube. This UV radiation when impinging on the white coating made of fluorescent materials coated inside the discharge column of the tube will generate white light(called daylight). Light output from a fluorescent lamp is moderate (60 lumens/watt) while the colour-rendering index is high. posat by Chinmoy kanjilal and Tushar dhara,research scientists,SMIT,Sikkim,India.
What else can I help you with?
Does milk contain sodium?
Milk does contain sodium. How much I couldn't tell you, it probably depends on the type of milk.
What does the weatherman tell us is she reffering to the amount of water vapor to the air?
Humidity describes how much water vapor is in the air. Humidity is what makes you feel sticky and moist on hot summer days.
What liquid leaves a residue of sodium chloride when evaporated?
Saltwater, which is a mix of water and dissolved sodium chloride, will leave a residue of sodium chloride when it evaporates. The water evaporates, leaving behind the salt as a white or clear crystal residue.
Calcium bromide plus sodium carbonate?
When calcium bromide reacts with sodium carbonate, a double displacement reaction occurs. Calcium carbonate and sodium bromide are formed as the products. The balanced chemical equation for this reaction is CaBr2 + Na2CO3 -> CaCO3 + 2NaBr.
What is frozen water vapor called?
well it is a long story for me to tell but we broke up yesterday after i ask him this question and he said you are so stupid it is rain you are such an messed up woman and we are through so what do u think let know.
How can you tell if a lamp is satin brass?
what is satin bras on a lamp
How can you tell if the halophane light you have is a metal halide or high pressure sodium?
If you have one or more of each type working, it is easy to tell the difference, a metal halide lamp produces a wide spectrum very white light, the high pressure sodium is a narrow spectrum light that is very yellow. If you just have the light fixture, and need to know what kind of lamp it is made for, the lamp type is often mentioned on the ballast nameplate or a small sticker near the lamp socket. If that does not work, a metal halide ballast will usually be two pieces, a transformer with a heavy laminated metal core, and a capacitor in a silver can. The sodium lamp ballast will have these also, but in addition it will have a lamp striker in a second silver can, or a plastic module. In other words Metal Halide ballast: 2 pieces, HPSodium ballast: 3 components.
Is sodium metal or nonmetal tell you?
Sodium is an alkali metal.
How can you tell the manufacturer of a table lamp?
its stamped on the bottom
How can you tell sodium chloride from sodium iodide?
NaI is solubale in acetone while NaCl is not soluable
What is a genie sim?
A Genie Sim is a Sim on the Sims 2 that you can get by getting the Genie Lamp. How do you get the lamp? I don't know. I'll tell you when I find out.
Can you tell me about a Cevin roman lamp with red table wine in it?
I have a Cevin Roman Lamp with Red Table Wine in it. I have had it for years. Is it worth anything?
How can you tell if sodium is low in your body?
One way to tell if sodium is low in your body is by experiencing symptoms such as fatigue, muscle cramps, headaches, and confusion. Additionally, a blood test can also determine if your sodium levels are low.
What is Pronunciation rebus for sodium?
Like at the pable table it tell you...
Why does sodium chloride is not like the elements that form it?
Just tell me!
How can you tell sodium hydroxide acted as a catalyst?
Sodium hydroxide anhydrous is used as a catalyst for the transesterification reactions of methanol and triglycerides.
Can you give me a command sentence using the word did?
I did tell you to fix that lamp so go do it now!
