【单选题】如图所示,已知U S1 =90V,U S2 =60V,R 1 =6 W , R 2 =12 W , R 3 =36 W ,用叠加定理计算 I 1 为( )
【单选题】下列各项中作为旅游业的基本构成要素之一,与旅行社、旅游交通、旅游景区等组成旅 游服务体系的是( )。
【单选题】如图所示的分压器,已知R1:R2=1:2,电源电压U S 为90V,将负载RL断开,U O 为A 2 ()
【单选题】如图所示某电路中的部分电路,各已知的电流及元件值已标示在图中电压源 U S 、电流 I 和电阻 R 分别为 ( )
【多选题】职业理想对社会发展的作用
A.
有明确的职业理想的高素质劳动者是社会发展的动力
【单选题】Despite its efforts, the newspaper industry still cannot satisfy the readers owing to its ______.
A.
failure to realize its real problem
B.
tendency to hire annoying reporters
C.
likeliness to do inaccurate reporting
D.
prejudice in matters of race and gender
【单选题】下列各项中作为旅游业的基本构成要素之一,与旅行社、旅游交通、旅游景区等组成旅游服务体系的是。
【单选题】如图所示,已知U S1 =90V,U S2 =60V,R 1 =6 W , R 2 =12 W , R 3 =36 W ,用叠加定理计算 I 2 为( )
【单选题】Despite its efforts, he newspaper industry still cannot satisfy the readers owing to its______.
A.
failure to realize its real problem
B.
tendency to hire annoying reporters
C.
likeliness to do inaccurate reporting
D.
prejudice in matters of race and gender
【简答题】如图2.7(a)所示。已知:U DD =-24V,R G1 =90kΩ,R G2 =25kΩ,R G3 =1MΩ,R D =R S =10kΩ,场效应管的I DSS =-2mA,U GS(off) =5V;电容 C 1 ,C 2 ,C 3 的值均足够大,对交流信号可以视作短路,信号源的内阻只R g =100kΩ。试求: (1) 从漏极输出时的电压放大倍数 及输出电阻r o1 值; (2) 从源极输...