Thus, a difference between a power flowing through {TAIL ~ the input wire} 7A and a power flowing through {HEAD ~ the output wire} 7B is big 
Thus , a difference between a power flowing through { TAIL ~ the input wire } 7A and a power flowing through { HEAD ~ the output wire } 7B is big
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH