Answer:
'''A lamp giving out 1200 lm in all directions is suspended 8 m above the working plane. Calculate the illumination at a point on
the working plane 6 m away from the foot of the lamp.'''
import math as m
I = 1200/(4*3.14) #Cd (luminous intensity of lamp)
h = 8.0 #m (height)
b = 6.0 #m (breadth)
length = m.sqrt(h**2 + b**2) #m
cosQ = h/length
E = I*cosQ/length**2 #lm/m^2
print "Illumination at point =",round(E,2),"lm/m^2 ."
Illumination at point = 0.76 lm/m^2 .
