Answer : Option D) 5 meters
Explanation :
To find the luminous intensity this formula is used;
Luminous intensity = illuminance ×
∴ Lv = Ev ×
We know the luminous intensity is 100 candelas and the illuminance is 4 lux.
∴ 100 = 4 x
∴ 100/4 =
∴ 25 =
∴ r =√25 = 5 meters
Therefore, the surface will be at a distance of 5 meters from the source.