A.The woman should call Bill to check his schedule. B.The woman should have left for the airport earlier. C.The woman does not need to rush to meet Bill. D.Traffic near the airport could delay the woman's arrival.
【简答题】放大电路如图15-45所示,晶体管为硅管,其β=80,信号源内阻R S =600Ω,U CC =12V,R B1 =20kΩ,R B2 =10kΩ,r be =1.62kΩ,R C =R L =5.1kΩ,R E1 =100Ω,R E2 =2kΩ。今测得U o =400mV。试求:(1)放大电路的输入电阻、输出电阻;(2)电源电压有效值为多少?
【简答题】在附图3.5所示交流电压放大电路中,已知U CC =12V,R B1 =20kΩ,R B2 =10kΩ,R C =2kΩ,R E =2kΩ,R L =6kΩ,晶体管的β=37.5,r be = 8kΩ。 (1) 计算放大电路的电压放大倍数A u 。 (2) 计算放大电路的输入电阻r i 。 (3) 计算放大电路的输出电阻r o 。