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The luminous flux of a monochromatic sou...

The luminous flux of a monochromatic source of 1 W is 450 lumen / watt. Find the relative luminosity at the wavelength emitted.

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The luinous flux of the given source of 2W is 4500 lumen/watt
`:. Relative luminousity
Luminous flux of the source
`=(of given wavelength)/(Luminous flux of 555 nm)`
source of same power
`=450/685=66%`
`[:.` since luminous flux of 555 nm source of 1W=685 lumen]`
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