Bl系列适用于交流50HZ,额定电压至250V额定电流 20A的低压操作控制电路,作线端连接分线和实验之用

A cosine voltage is zero and increasing at t=-1 6ms; the next zero crossing occurs at t 4.65ms. (a)Calculate T, f, and @.(b) If v(0)=20V, find v(t).(c)By what angle does v(t) I(t)=5cos(t-110°)A? 2 For the sinusoidal waveform shown in

一、（1）× （2）√√ （3）√× （4）× （5）√ 二、（1）A A （2）D A （3）B A （4）D B （5）C B 三、（1）B D （2）C （3）A

A point at which two or more elements have common connection is called node(节点). Suppose that we start at one node in a network and move through a simple element to the node at the other..., if no node was encountered more than once, then the set of nodes and elements that we have passed hrough is defined as path(路径)

一、判断下列说法是否正确,用“√”或“”表示判断结果。 (1)在图T8.1所示方框图中,若中F180°,则只有当中A=±180°时,电路才能产生正弦波振荡。()

第一部分选择题(共30分) 一、单项选择题(本大题共10小题,每小题3分,共30分) 在每小题列出的四个选项中只有一个是符合题目要求的.请将其代码填在题后的括号内。错选或未选均无分。 串联谐振电路,固有谐振频率取决于 A电源电压幅值 B电源电压的初始相位 C.电源电压频率

1 At a frequency of 796 Hz, compute Zo,u and for a line having the following parameters: F2230 u H/km,=0.0055 u F, r-6./km, g negligible. 2 At certain frequency, transmission line has Zo=5560°andy=0.005+j0.03np/km The line is 60 km long. A sinusoidal voltage of 100V at the specified frequency is applied to one end. Find:

1、一个40KW、10Q的电阻,使用时至多能容许A的电流通过。 2、若流入某一节点有4个电流,已知i1=5A,i2=2A,3=-3A,那么

一、判断下列说法是否正确,用“√”或“×”表示判断结果。 (1)在图T8.1所示方框图中,若中F=180°,则只有当中A=±180° 时,电路才能产生正弦波振荡。()

In the chapter we shall develop a method for representing a sinusoidal forcing function or a sinusoidal response by a complex number called a phasor transform,or simply a phasor. By working with phasors we shall effect a truly remarkable simplification in the steady state sinusoidal analysis of general circuits