According to Lambert's law, a light-emitting luminaire is hemispherical and the bulb inside produces a flux of 9275 lumens. The transmittance factor of the luminaire, which is opal glass, is 0.7.The diameter of the luminaire is 20 cm. This luminaire is placed in the centre of a 4m x 4m room, zero to the ceiling. The height of the room to be illuminated from floor to ceiling is 3.17 metres.
a. Calculate the illuminance level at any corner of the room 0.8 metres above the floor.
