
#1
Jun2506, 02:14 PM

P: 424

Please help me with this problem.
# An isotropic point source of 100 candela is fastened to the ceiling of a room. What is the total luminous flux falling on all the walls and floor? I solved it in the following way: Here Luminous intensity(I) = 100 cd, Total solid angle(w) = 2 (pi) steradian Total luminous flux falling on all the walls and floor = I x w = 100 x 2(pi) = 100 x 2 x 3.14 = 628 lumens Is it right? 



#2
Jun2506, 07:11 PM

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#3
Jun2606, 02:38 AM

P: 424





#4
Jun2606, 05:27 AM

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Luminous flux problem 



#5
Jun2606, 11:44 AM

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Solid angle(w) = Area of hemisphere/R^2 = [2(pi)R^2]/R^2 = 2(pi) steradians I think radian is a 2 dimensional unit whereas steradian is a 3 dimensional unit of angle. I may be wrong. 



#6
Jun2606, 07:22 PM

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#7
Jun2706, 01:13 AM

P: 424

That's ok. Thanks.



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