As the circuit shown in the figure, the line voltage of balanced three phase source is U˙AB=380∠30oV and the impedances are Z1=50+j50Ω，ZA=ZB=ZC=50+j100Ω

单选题

G parameters of the following circuit is:

单选题

Multiple selection problem
(one option)
For the convolution integral of the following two functions, how many time segments are required when ?

问答题

In the figure,the current of current source IS=[填空1](A)?

IS=

单选题

How many sub-circuits do we need to analyze for finding the solution of the previous circuit?

问答题

Fill in the blank
For the one-port network with associated current and voltage directions, its rms voltage is 100V and rms current is 50A. Its received apparent power S=[填空1]VA.

问答题

As the circuit shown in Fig. 10-1,【1】its characteristic roots are p1=[填空1], p2=[填空2].

问答题

As the circuit shown in the figure, the line voltage of balanced three phase source is U˙AB=380∠30oV and the impedances are Z1=50+j50Ω，ZA=ZB=ZC=50+j100Ω 问答题

As the circuit shown in the following figure, the initial energy stored in capacitor is zero and the controlled voltage source is current-controlled voltage source. S is switched from a to b at t=0. Solve: (1)When t＝4.5s, the capacitor voltage uC=[填空1]V; (2) When t＝4.5s, the current i1=[填空2]mA.

单选题

If a device is driven by current signal, what is the ideal value of its input resistance?

问答题

(Simulation) The balanced bridge is also quite useful in control systems. Let us take the temperature control system as an example. Suppose we have a thermistor whose resistance R is in direct proportion to the environment temperature. That means when the temperature increase ΔT centidegree, the resistance of the thermistor will raise ΔR ohm accordingly. The V in the circle in the following Figure is a voltmeter with very large resistance. It is clear that the voltmeter will have zero value when ΔR=0.



If the environmental temperature causes the thermistor changing its resistance to R+ΔR, the bridge is not balanced anymore. Deduce the expression of voltmeter’s voltage, find the voltage using any of your simulation software, and fill in the blank uV=[填空1]mV with uS=10V, R=10kΩ, and ΔR=10Ω:

问答题

For the one-port sub-circuit, the average value of voltage u=[填空1]V,   the rms value of voltage u=[填空2]V,   the average value of current i=[填空3]A,   the rms value of current i=[填空4]A,   and the average absorbed power of the one-port is =[填空5]W.

单选题

With regard to a circuit with n nodes and b branches, (2) How many KVL equations are required?

单选题

The figure shows four circuits. Answer the following questions.When , the circuits represent the characteristic of open circuit are shown in Fig ______.

问答题

The current I in the circuit is[填空1]A.

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For the sub-circuit, the equivalent impedance seeing from the primary side is
Zeq=[填空1]Ω.

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传统社区是人服从于技术,智慧社区是技术服务于人。( )

问答题

智慧的技术有助于推动社区中的垃圾分类。

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电影《少数派报告》表明,未来是不可预知的。( )

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智慧交通已成为未来交通运输业优先发展地主题。( )

单选题

相对于传统政府的垂直化层次结构,电子政府体现的是( )。

问答题

网上预约等服务一定程度上能解决看病难，看病贵的问题

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互联网+政务服务就是电子政务在新时代的称呼

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智慧教育的重点在于智慧。

问答题

智慧社区是一种新型的社区形态。( )