I B.Tech - Regular Examinations, June 2009
First Year
Netwrok Analysis - SET NO: 1
(Regulation 2007)
Time : 3 hours |
Maximam Marks:80 |
Answer any FIVE Questions
1. A circuit consisting of three resistances 12Ω
, 18Ω
and 36Ω
respectively joined in
parallel is connected in series with a fourth resistance. The whole circuit is applied
with 60V and it is found that the power dissipated in the 12Ω
resistor is 36 W.
Determine the value of the fourth resistance and the total power dissipated in the
circuit.
2. The number of turns in a coil is 20. When a current of 2A flows in this coil, the
flux in the coils is 0.3 mwb. When this current is reduced to zero in 2 milli seconds,
the voltage induced in an adjacent coil is 63.75V. If K = 0.85, find self inductances
of the two coils, mutual inductance and number of turns in the second coil.
3. A balanced 3 phase star connected load of 150kW takes a leading current of 100A
with line voltage of 1100 volts, 50 Hz. Find the circuit constant of the load per
phase.
4. For the network, shown in figure 4 draw the oriented graph and obtain the cut set
matrix.
5. (a) State and explain Thevenin’s Theorem.
(b) What are the limitations of Thevenin’s Theorem.
(c) Explain the steps to apply Thevenin’s Theorem and draw the Thevenin’s
equivalent circuit.
6. For the two port network shown in the figure 6, the currents I1 and I2 entering at
port 1 and 2 respectively are given by the equations.
I1I = 0.5 V1 - 0.2 V2, I2 = -0.2V1 + V2
Where V1 and V2 are the port voltages at port 1 and 2 respectively. Find the Y,
Z, ABCD parameters for the network. Also find its equivalent II network.
7. In the circuit shown in figure 7, Eg (t) = 2.5 t Volts. What are the values of i(t)
and VL(t) at t = 4 seconds.
8. A high pass filter section is constructed from two capacitors 1 µF each and a
15 mH inductance. Find the cut - off frequency, infinite frequency characteristic
impedance and characteristic impedance at 200 Hz, attenuation at 200 Hz and
phase shift constant at 200 Hz.
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