[单选题]安全超低电压(SELV)和功能超低电压(PELV)的标称电压为()。A . ≤24VB . ≤36VC . ≤50VD . ≤100V
[名词解释] SELV回路(SELV circuit)
[名词解释] 一回路 primary circuit
[名词解释] 二回路 secondary coolant circuit
[问答题] GIS就地控制屏上发“跳闸回路A/B闭锁(TRIP CIRCUIT A/B BLOCKED)”报警的原因有哪些?
[试题]C.ircuit Switching is problematic because data communications is(),that is, it is typically dominated by short bursts of activity with long periods of().A.reliable B.bursty C.digital D.continuous A.latency B.transmission C.delay D.inactivity
[单选题]A heater in the circuit facilitates warning of the engine prior to () by circulating hot water.A . startingB . stoppingC . to startD . to sto
[名词解释] VC(Virtual Circuit)虚电路
[单选题]Circuit-switching technology is used in Publish Switched Telephone Network(PSTN), Global System for Mobile Communications(GSM) and code Division Multiple Access (CMDA) . It is a ( ) information transfer mode.A . connection orientedB . connectionles
[单选题]Sequential circuit is a common logic device whose output values, at a given instant, depend upon its input values and the internal state at that instant, and whose internal state depends upon the(66)preceding input values and the preceding internal s