The luminous flux of a monochromatic source of 1 W is 450 lumen watt−1. Find the relative luminosity at the wavelength emitted.
A source emits light of wavelengths 555 nm and 600 nm. The radiant flux of the 555 nm part is 40 W and of the 600 nm part is 30 W.The relative luminosity at 600 nm is 0.6 . Find (a) the total radiant flux, (b) the total luminous flux, (c) the luminous efficiency.