如图7-19所示电路，正弦电流i2的有效值I2=1A，电流i3的有效值I2=2A，因此电流i1的有效值I2等于（）。https://assets.asklib.com/psource/2015110111092591179.jpg

A . 1 B . 2 C . 3 D . 不能确定

A . 180° B . 120° C . 90° D . 60&deg

A . 0 B . Π/6rad C . Π/3rad D . 2Π/3rad

A . 4B . 8C .https://assets.asklib.com/psource/2015110113464233665.jpg D . 2

A . A B . B C . C D . D

A . 2.5A和1.5A B . 1A和0A C . 2.5A和0A D . 1A和1.5A

A . ['2B . 1C .https://assets.asklib.com/psource/2015110111083885238.jpg D .https://assets.asklib.com/psource/201511011108524289.jpg

A . A、3A B . B、1A C . C、3A

A . 10 B . 11.3 C . 14.1 D . 19.8

A . I1=20A，I2=20A，I320A B . I1=10A，I2=20A，I3=5A C . I1=10A，I2=5A，I3=20A D . I1=5A，I2=5A，I3=5A

已知如图所示电路中I₁=I₂=10A。求<img src='https://img2.soutiyun.com/ask/2019-12-11/94494300886036.png' />。 <img src='https://img2.soutiyun.com/ask/2019-12-11/944943016444169.png' />

如图7-17所示电路中，电流I1和电流I2分别为（）。 A.2.5A和1.5A B.1A和0A C.2.5A和0A D.1A和1.5A<img src='https://img2.soutiyun.com/ask/uploadfile/4515001-4518000/b778ebde3cc29c066704bdf98c1dbaad.jpg' />

如图1．3．16所示电路为晶体管放大器等效电路，电路中各电阻及β均为已知，求电流放大系数Ai(Ai=i2/i1)、电压放大系数Au(Au=u2／uS。 <img src='https://img2.soutiyun.com/ask/uploadfile/5385001-5388000/7e6ad554669d6eb2c2594eab2bfde8ab.jpg' />

试用网孔电流法求解图题12-4所示电路中的电流i2(t)。 <img src='https://img2.soutiyun.com/ask/2020-07-24/96445499368431.png' />

<img src='https://img2.soutiyun.com/1/2020-09-25/969878575499131.png' /> A、I1=20A，I2=20A，I3=20A B、I1=10A，I2=20A，I3=5A C、I1=10A，I2=5A，I3=20A

在图2.05所示的电阻R1和R2并联的电路中，支路电流I2等于()。 <img src='https://img2.soutiyun.com/ask/2020-06-19/961428053143973.png' /> (1)<img src='https://img2.soutiyun.com/ask/2020-06-19/961428068284839.png' />(2)<img src='https://img2.soutiyun.com/ask/2020-06-19/961428077767382.jpg' />(3)<img src='https://img2.soutiyun.com/ask/2020-06-19/961428109246182.png' />

<img src='https://img2.soutiyun.com/shangxueba/ask/50871001-50874000/50873953/968489998268042.png' />

<img src='https://img2.soutiyun.com/ask/2020-09-09/968489840977045.png' />

<img src='https://img2.soutiyun.com/shangxueba/ask/18756001-18759000/18757223/2016071815235556431.jpg' /> A．10 B． 12 C． 14 D． 16

A．10 B．12 C．14 D．16

题图11-29所示电路中，<img src='https://img2.soutiyun.com/ask/2020-07-07/962978637698644.png' /><img src='https://img2.soutiyun.com/ask/2020-07-07/962978650466374.png' />试求每个电阻电流的瞬时值表达式i2(t)、i4(t)，电阻电流的有效值以及电阻吸收的平均功率。 <img src='https://img2.soutiyun.com/ask/2020-07-07/962978663428116.png' /><img src='https://img2.soutiyun.com/ask/2020-07-07/962978671296566.png' /><img src='https://img2.soutiyun.com/ask/2020-07-07/962978677442917.png' />