【简答题】Q.1 A 220 kV, 50 Hz, three-phase, 60 km transmission line supplying a star-connected load of 240 MW with a power factor of 0.8 lagging is shown below. The line has the following parameters: • r = 0.15...
【单选题】In multipoint networks , there are tree persistence methods when a station finds a channel busy.in the 1-persistent method,after the station finds the line idle,it sends its frame immediately.this met...