512 ALTERNATING CURRENTS 



182. Find the mean spherical candlepower and the output in lumens of 

 the lamp in problem 180 if it has a spherical reduction factor of 0.82. 



183. If the lamp of problem 182 is equipped with a reflector which 

 absorbs 25 per cent, of the light emitted by the source, determine the mean 

 spherical candlepower and the lamp output in lumens. 



184. A lamp is tested for candlepower and the polar and Rousseau dia- 

 grams are plotted. The area of the Rousseau diagram is 14.2 sq. in. and the 

 base is 6 in. The scale on the polar diagram is 20 candlepower = 1 in. 

 What is the mean spherical candlepower and the output of the lamp in 

 lumens? 



186. If the 90 radius problem 184 (see Fig. 396, page 440) is 3 in. and 

 represents the mean horizontal candlepower of the lamp, what is the spher- 

 ical reduction factor of the lamp? 



OF APPLIE, 



