The indoor illumination requirement for a building is 350

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The indoor illumination requirement for a building is 350 Lux. If the daylight factor is 2.7 and the design sky illuminance is 9000 Lux, then the required supplementary artificial lighting is ____________ Lux.

1. 107 to 107
2. 108 to 108
3. 109 to 109
4. 110 to 110

Correct Option: A

107 to 107
Explanation: The three components contributing to daylight factor are: (a) sky component (SC), (b) externally reflected component (ERC), and (c) internally reflected component (IRC).
Thus, DF = SC + ERC + IRC
Daylight factor is also defined as the ratio of indoor illumination to the corresponding outdoor illumination can be taken as constant.
This constant ratio, expressed in percentage, is the daylight factor (DF), given by :

DF =		E_i		× 100
		E₀

where, E_i = indoor illumination at the point of consideration & E_o = outdoor illumination from unobstructed sky.
Here, DF = 2.7, Eo = 9000 Lux.
Assume the existing indoor illumination (E_i) = ‘P' Lux.