An extended source emits light at 600 nm producing irradiance of 7 w/m2. the relative luminous efficiency at 600 nm is about 0.75 producing 0.75 x 685 lumens per watt. calculate the illuminance of this source. b) (5 marks) a certain small object emits monochromatic light with luminous intensity of 100 candela (cd). calculate its radiant intensity assuming that the relative luminous efficiency at this wavelength is 0.5. c) (5 marks) the luminance of a flat plate at 555 nm (at the maximum of the relative luminous efficiency curve) is 10 im/m2 sr. calculate its radiance. d) (5 marks) the diode a has the luminous intensity of 10 candela (cd) and it emits light in a solid angle of 0.053 sr. the relative luminous efficiency within its wavelength range is approximately 0.7. the diode b has the luminous intensity of 5.6 candela (cd) and it emits into a solid angle of 0.15 sr. the relative luminous efficiency within its wavelength range is 0.15. calculate the power of light from each diode. which diode (a or b) has higher power?