Correct Answer - Option 1 : 1 lux
Concept:
Illumination is defined as the luminous flux received by the surface per unit area.
It is usually denoted by the symbol ‘E’ and is measured in lux or lumen/m2 or meter candle or foot candle.
Illumination, \(E = \frac{\phi }{A} = \frac{{CP \times \omega }}{A}lux\)
Solid angle \(\omega = \frac{A}{{{d^2}}}\)
Illumination \(E = \frac{{CP}}{{{d^2}}}lux\)
Calculation:
Given that,
Illuminance = 64 π
\(E= \frac{P}{4\pi r^2}=\frac{64\pi}{4\pi(4)^2}= 1\;lux\)
