The luminous flux of a monochromatic source of 1 w is 450 lumen
. Find the relative luminosity at the wavelength emitted.
Given,
The luminous flux of the given source is 450 lumen/watt.
We know that luminous flux of 555 nm source of 1 W = 685 lumens
∴ 
So, the relative luminosity at the wavelength emitted is 66 %.
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