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(ELEC102)test2_pastd.pdf
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Text Box: Find .. and .. Does V2 (t) lag V1 (t) ? Given period of V2 (t) is 18ms , and difference between the pe
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2

(2.5)

(2)

(5)

(2)

(2.5)

(3.5)

(2.5)





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3

3k.

24V

3k.

6k.

3k.

24V

3k.

6k.



4

(13)

(3)

(4.5)

(5.5)



Text Box: In the circuit,Find Vo in Vrms . (13)






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5

(3)

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(3)




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6

(5)

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(5)

(4.5)

(5.5)



Text Box: Show that the open circuit voltage at terminal ab is 6.0o V. Find the Thevenin impedance and hence use Thevenin





Text Box: Thevenin impedance, Z = 1- j ..





(6)

(6)

(b)

(c)

(d)

(7)

(6.5)

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(6.5)

(6)





Text Box: P = real (or average) power dissipated by load S = power supplied by source to load ZQ = power stored in Z
Text Box: Load A is connected in parallel to a 200Vrms, 50 Hz supply as shown. Power factor PF of load A is 0.8 lagging. S =








8

(7)

(15)






Text Box: Find V2 (15)
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(21)

9

(3)

(5)

(6)

+
VO
-

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+
Vi
-



Text Box: Ro = 0
Text Box: (a) Draw the circuit model for a voltage amplifier.What is the ideal value of the output resistance?



Text Box: (b) Explain briefly why for ideal op amp, the Vi and Ii are ~ 0. (21)



(7)

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10

I






Text Box: In the instrumentation amplifier, find Vo/ (V2 - V1) in terms of R2 and R . Name also two advantages of this
Text Box: High input resistanceChange voltage gain by only 1 R