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Question
A light source emits monochromatic light of 555 nwavelengthm. The source consumes 100 W of electric power and emits 35 W of radiant flux. Calculate the overall luminous efficiency.
Solution
Given:
Wavelength of light, λ = 555 nm
Radiant flux emitted = 35 W
Power input = 100 W
Overall luminous efficiency = `"Total luminous flux"/"Power input"=(35xx685)/100=239.75 "lm/W"`
So, the overall luminous efficiency will be 240 lm/W.
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