Analytical. Study of the Alternating Current Arc. 343 

 Fig. 9. — Intensity of Light from Centre of Arc. 



Frequency * 20 nw 

 Length of Arc = 32cm 



20 



SeetadlelTA / \ 



/ V 



Nt 



0) 



I- 



o^ 



Angle of Phase 



20 40 



\h 80 100 120 140 160 180 200 220 //240 260 280 300 320 340 3 

 \ 



m *- 



Time 



70 



60 



50 



10 



60 



