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(ELEC102)test2_pasth.pdf
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Text Box: In the circuit, X is an unknown element. (32)








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Text Box: I leads V

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The circuit is at steady state for t < 0. At t = 0, the switch is switched from A to B (i.e. BC is shorted). (a) Find i(t) for t 0. (b) Find the maximum energy stored in L. (c) Plot V(t) for t < 0 and t 0. Label clearly the voltage and time. (33)

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Text Box: V(t)



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The circuit is at steady state for t < 0. At t = 0, the switch is closed. (a) Find V(0), V() and time constant for t > 0. (b) Plot IO(t) for t < 0 and t 0. (25)

IO(t)

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18V

4k.

2k.

V(t)

IO(t)













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magnitudeVm2V



Text Box: At bandwidth, V1 .l 0.7 x 1.4 Vrms
Text Box: bandwidth .l 1kHz
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Text Box: In the circuit, V1 versus log-frequency f is given as shown. Find roughly the magnitude of VS in V, bandwidth of D

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Text Box: Find .. and . . Show that V2 (t) is roughly - 3.5V when t = 2ms. Does V2 (t) lag V1 (t) ? Given 2. radian

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Text Box: (a) . Find i(t). (12)



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Text Box: (b). Find VL in Vrms and I in Arms. (15)






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Text Box: Use voltage divider


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voltage follower

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Text Box: (a). Find the value of VS2 . Assume op amp is ideal. (18)


Text Box: (b) Draw the circuit of an op amp voltage follower and name two advantages of the circuit. (12)

Text Box: (b)





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Text Box: Find VO. Show clearly all your steps. Assume op amp is ideal. (30)
Text Box: V1 = 2V

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Text Box: Find V phasor
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Text Box: Find frequency f of v(t)

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Text Box: Find period of v(t)




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Text Box: Find impedance Z

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Text Box: 4..
Text Box: 6j..
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Text Box: A parallel LCR tuner circuit is used to receive radio stations as shown in the resonance curve. (a) Find in Hz the



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Text Box: Circuit is in resonance








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Text Box: load B is capacitance





Text Box: power factor of load A = PF
Text Box: (c)
Text Box: Electric fees is related to P onlyP