【简答题】如题5.40图是二阶有源滤波器,其输出端开路,图中理想放大器K的输入阻抗为无限大,输出阻抗为零,放大倍数为K。当R1=R2=1 Ω,C1=C2
【简答题】下图所示电路中,运算放大器为理想的,R w 为电位器。试证明ab间的等效电容C ab =(1-k)C,式中k为电位器R w 的分压系数。
【简答题】Some researchers can not test their hypotheses by experiments because of ______.
【简答题】For what a purpose did the researchers use raw potato starch in their experiment?
【单选题】Researchers have found that migrating animals use a variety of inner compasses to help them navigate. Some (1)_____ by the position of the Sun. Others navigate by the stars. Some use the Sun as (2)___...
【简答题】如题图为谐振功率放大器的电路图。其中,电容C 0 为旁路电容,R 1 为产生自偏压的电阻,RFC为高频扼流圈,R 1 为负载电阻,LC回路谐振于输入信号v i (t)的频率f c 。若晶体管的转移特性如题图所示,输入信号v i (t)=V im cos2πf c t。已知晶体管集电极电流余弦脉冲的峰值为20mA,流通角为60°,试计算自偏压V B 的值、电阻R 1 的值、输入电压的幅度V im 和...
【简答题】The way a lot of researchers use to study anxiety is by ______.
【判断题】每一个线性方程组都与一个阶梯型方程组等价。()