The Area A1 is 3.14 m2, The Lamp #1 has a Luminous flux 400 lumens, and the Distance D1 is 4 meters.What is the illuminance on the A1 (the Lamp#2 is off) **Problem Statement:**Given the following spotlights placed as shown in the diagram. Assume isometric distribution of the light.- The Area A1 is 3.14 m².- The Lamp #1 has a Luminous flux of 400 lumens.- The Distance D1 is 4 meters.What is the illuminance on the A1 (the Lamp #2 is off)?**Diagram Explanation:**The diagram displays two lamps, Lamp #1 and Lamp #2, positioned above three areas labeled A1, A2, and A3. Both lamps have specified beam angles (ϕ), and each light illuminates the area directly under it. Lamp #1:- Positioned directly above area A1.- Illuminates a circular area with a specified angle.Lamp #2:- Positioned to the side, affecting areas A2 and partially overlapping with A3.- For this problem, Lamp #2 is off.Distances:- D1 is the distance from Lamp #1 to A1.- D2 is the distance from Lamp #2 to its effective areas.The illuminance on area A1 is to be calculated from Lamp #1. Since Lamp #2 is off, it does not contribute to the illuminance on A1.

Illuminance is defined as the measure of illumination on the given surface by the incident light. It is mathematically expressed as total luminous flux incident on per unit surface area. E=ϕA ....(1) where, ϕ, is the luminous flux and A, is the surface area The data provided is as follows, A1=3.14 m2ϕ=400 lumensD1=4 m When lamp 2 is off, the illuminance on A1is calculated in the following manner, Substitute the values in equation (1), E=400 lumens3.14 m2 =127.39 lux