【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...
【简答题】The world of the science-fiction 3-D film Avatar is so perfect that the line between fact and fiction has become somewhat blurred (模糊) . Movie-goers have admitted being annoyed by depression at not be...
【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...