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A point source emitting light uniformly ...

A point source emitting light uniformly in all directions is placed above a table-top at a distance of 0.50m from it. The luminous flux of the source is 1570 lumen. Find the illuminace at a small surface area of the table top (i) directly above the source and (ii) at a distance of 0.80 m from the source.

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A point source emitting uniformly in all directions is placed above a table top at a distance of 0.50 m from it. The luminous flux of the source is 1570 lumen. Find the illuminance at a small surface area of the table to a.directly below the source and b. at as distance of 0.80 m from the source.

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