Upon closure of {HEAD ~ the switch S1}, an a.c. voltage is induced in {TAIL ~ the secondary windings} 14 and 15 of transformer 1 with the result that a current will flow in the filaments 21 and 22 of fluorescent lamp 2 which will in turn be heated 
Upon closure of { HEAD ~ the switch S1 } , an a.c . voltage is induced in { TAIL ~ the secondary windings } 14 and 15 of transformer 1 with the result that a current will flow in the filaments 21 and 22 of fluorescent lamp 2 which will in turn be heated
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH