The Open University of Sri Lanka

Department of Electrical and Computer Engineering

Diploma in Technology – Level 3

ECX 3231 - Electrical Circuits and Measurements

Academic year 2012/2013

Assignment 2

To be submitted on or before 22nd

February 2013

Q1)

Fig. 1

For the four-terminal network shown in Fig. 1 determine,

a) The y parameters.

b) The ratio of the output and the input voltages when no load impedance is present.

c) The value of the frequency at which the output voltage is zero.

Q2)

a) Briefly explain the applications of Spectrum analyzers and Logic analyzers.

b) Describe the operational principle of a Digital Storage Oscilloscope and Function

generator.

c) Derive an expression for the torque develops in a moving iron instrument.

d) List advantages and disadvantages of using analogue multi meter when compared

with digital multi meters.

e) Briefly explain the role of computer tools in circuit analysis.

Q3)

a) The driving point impedance function of a reactive network is as follows, develop

the two fraction networks.

b) Synthesize the first and second Foster networks for the impedance function.

I1 I2

1’ 2’

1 2

V1 V2

Q4)

a) Compare characteristics of Active and Passive filters.

b) What are the disadvantages of Passive filters?

c) Calculate the values of the shunt and the series elements of a high-pass π section

filter having a cut-off frequency of 10 kHz. The nominal resistance of the filter is

500Ω.

d) The Operational amplifier shown in Fig.2 is an ideal one and circuit is operating at

the sinusoidal steady state condition.

Fig.2

i. Derive the transfer function of the circuit.

ii. State the function of the circuit by inspecting the transfer function.

Vin Vo