In electricity, the alternation of the direction of current flow, generally expressed as cycles per second In the U S , most household current alternates at 60 cycles per second Also known as "hertz "
Contain N nodes and N edges Edges may be written: e1 {v1, v2} e2 {v2, v3} e(N-1) {v(N-1), vN} eN {vN, v1} Symbol: C_N (C sub N)