【简答题】图3-16所示单相桥式全控整流电路,接大电感负载,U 2 =220V,R d =4Ω,试计算当α=60°时,输出电压、电流的平均值。如果负载端并接续流二极管,输出电压、电流的平均值又为多少?并求流过晶闸管和续流二极管中电流平均值、有效值以及画出两种情况下的电流、电压波形图。
【单选题】136 You have been assigned as a project leader and must first review the statement of work provided by the customer. Which of the following is most often overlooked?
A.
Data item deliverables
B.
Customer-furnished equipment and facilities
C.
Long-lead procurement items
D.
Customer-imposed milestones
E.
Other subcontractor interface requirements
【单选题】属于疫苗接种异常反应的是
D.
合格疫苗在实施规范接种过程中造成机体器官功能损害
E.
受种者在接种时正处于某种疾病的潜伏期或前驱期,接种后偶合发病
【单选题】单相桥式全控整流电路,大电感负载,电感量足够大。已知U2=100V,R=2Ω,当【图片】时,整流输出平均电流值为( )
【多选题】单相桥式全控整流电路,负载R=2 Ω ,L很大,反电动势E=60V,U2=100V, α =30度,输出的电压为( )、电流为( )。