Visible spectrum of the light has a wavelength in the range of:A. 1000 to 4000 Ao B. 4000 to 7000 Ao C. 7500 to 12500 Ao D. 12500 to 30000 Ao 82. Luminous flux is:

• A. the rate of energy radiation in the form of light waves
• B. the part of light energy radiated from light source
• C. measured in lux
• D. both a and c