Question
Download Solution PDFLuminous efficiency of a fluorescent lamp is
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFLuminous efficiency: It is also known as radiant efficiency. It is defined as the ratio of energy radiated in the form of light, which produces the sensation of vision to the total energy radiated out by the luminous body.
Radiant efficiency = energy radiated in the form of light / total energy radiated by the body
Lamp efficiency is measured in lumen/watt.
Important Points:
|
Lamp |
Lamp efficiency |
|
Carbon filament lamp |
3 – 4.5 lumen/watt |
|
Osmium filament lamp |
5 lumen/watt |
|
Tantalum filament lamp |
2 lumen/watt |
|
Tungsten filament lamp |
18 lumen/watt |
|
Carbon arc lamp |
9-12 lumen/watt |
|
Flame arc lamp |
8 lumen/watt |
|
Neon discharge lamp |
15 – 40 lumen/watt |
|
Sodium vapour lamp(low pressure) |
101-175 lumen/watt |
| Sodium vapour lamp(high pressure) | 67- 121 lumen/watt |
|
Mercury vapour lamp |
30 – 40 lumen/watt |
|
Fluorescent lamp |
50–60 lumen/watt |
|
Incandescent lamp |
8 – 40 lumen/watt |
Last updated on Jun 24, 2025
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