A、如图所示为电桥电路,已知R<sub>1sub>=1Ω、R<sub>2sub>=2Ω、R<sub>3sub>=2Ω、R<sub>4sub>=4Ω、R<sub>5sub>=5Ω,试求等效电阻R<sub>absub>。r /> rc="https://img.ppkao.com/2018-05/tangxueping/2018051015543465216.jpg" />
A、如图所示为电桥电路,已知R<sub>1sub>=1Ω、R<sub>2sub>=2Ω、R<sub>3sub>=2Ω、R<sub>4sub>=4Ω、R<sub>5sub>=5Ω,试求等效电阻R<sub>absub>。r /> rc="https://img.ppkao.com/2018-05/tangxueping/2018051015543465216.jpg" />
A、充电式延时电路如图所示,其中E<sub>csub>=18V,U<sub>Vsub>=10V,C=47μF,若要使该电路延时1s,试求充电电阻R<sub>2sub>的值。r /> rc="https://img.ppkao.com/2018-09/tangxueping/2018093015351571478.jpg" />
A、如图所示电路为何种电路?当输入信号u<sub>ssub>与U<sub>csub>的波形如图所示时,画出u<sub>osub>在加电容C前后的波形。r /> rc="https://img.ppkao.com/2018-09/tangxueping/201809131005477043.jpg" />
A、已知电路如图所示,其中E<sub>1sub>=15V,E<sub>2sub>=65V,R<sub>1sub>=5Ω,R<sub>2sub>=R<sub>3sub>=10Ω。试用支路电流法求R<sub>1sub>、R<sub>2sub>和R<sub>3sub>三个电阻上的电压。r /> rc="https://img.ppkao.com/2018-09/tangxueping/2018092817031193342.jpg" />
A、电路如图所示,已知稳压管的稳定电压为6V,最小稳定电流为5mA,允许耗散功率为240mW;输入电压为20~24V,R<sub>1sub>=360Ω。试问:r /> (1)为保证空载时稳压管能够安全工作,R<sub>2sub>应选多大?r /> (2)当R<sub>2sub>按上面原则选定后,负载电阻允许的变化范围是多少?r /> rc="https://img.ppkao.com/2018-09/yuanhao/20180911103835413.jpg" />
A、如图所示电路中,u<sub>Ssub>=10sin314tV,R<sub>1sub>=2Ω,R<sub>2sub>=1Ω,L=637mH,C=637μF,求电流i<sub>1sub>,i<sub>2sub>和电压u<sub>csub>。r /> rc="https://img.ppkao.com/2018-09/tangxueping/2018092818010827576.jpg" />