Third Semester B.E. Degree Examination, Dec 2018
17EE 32ELECTRICAL CIRCUIT ANALYSIS
Time: 3 hrs. MODEL PAPER Max. Marks: 100
Note: Answer FIVE full questions, choosing one full question from each module
Module 1
1 a. Perform source transformation and find a single voltage source in series with a
resistance for the circuit shown in fig
Fig
6 marks
b. For the circuit shown in fig solve for loop currents
Fig
6 marks
c. Find the equivalent delta connection for the circuit shown in fig
fig1(c)
8 marks
OR
2 a. Find the current in the 10 Ohm resistor for the circuit shown in fig Use star
delta transformation.
Fig
6 marks
b. For the circuit shown in fig determine all node voltages. 8 marks
Fig
c. The node voltages equations for an electrical circuit are as follows:
Draw the circuit.
6 marks
Module 2
3 a State and explain superposition theorem. 6marks
b For the circuit shown in fig find the Thevenin's equivalent circuit across XY
terminals.
Fig
8 marks
c For the circuit shown in fig find the Norton's equivalent across X-Y
terminals.
Fig 3
4 marks
OR
4 a State and explain Norton's theorem 6 marks
b In the network shown in fig. determine the current I using superposition
theorem.
Fig 4
8 marks
c Find Vx and verify reciprocity theorem for the circuit shown In fig 4
Fig 4
6 marks
Module 3
5 a A series circuit is energized by a variable frequency AC supply. Derive the
expressions for half power frequencies and bandwidth.
8 marks
b For the circuit shown in fig find the frequency at which the circuit will be at
resonance. If the capacitor and inductors are interchanged, what will be the
6 marks
value of the resonance frequency?
Fig
c Explain the behavior of circuit elements under switching action(t 0 and
infinity),
6 marks
OR
6 a Determine di/dt and d2i/dt2 at t when the switch is moved from
position 1 to position 2 in the circuit shown in fig.6(a)
Fig 6
8 marks
b In a series RLC circuit, the resistance, inductance and capacitance are 10 ohms,
100 mH and 10 microfarad. Calculate ω0, ω1 and ω2. Also find bandwidth and
selectivity.
7 marks
c Show that the circuit shown in fig 6 resonant at supply frequency.
Fig
5 marks
Module 4
7 a State and prove initial value and final value theorems 8 marks
b Show that the Laplace transform of a periodic function is e times the
Laplace transform of the first pulse. Where T is the period of the function.
6 marks
c Obtain the Laplace transform of the pulse shown in fig.
Fig
6 marks
8 a Determine the Laplace transform of half rectified sine wave of maximum value
V
6 marks
b Evaluate the Laplace transform of the periodic signal shown in fig.
Fig
6 marks
c Find the initial value and final value of the following functions:

















8 marks
Module 5
9 a The delta connected load impedance shown in the fig.9(a) is supplied by a
balanced 400 V three phase 50Hz supply. Phase sequence is RYB. Determine
8marks
the phase and line currents.
Fig 9
b Find the z parameters for the network shown in fig. 9
Fig.9
6 marks
c Find Y11, Z21,h21 and D from
2V1 4 I2 I1
8 I2 V2 6V1
6 marks
OR
10 a For the network shown in fig. 10 determine Y and Z parameters
Fig.10
8 marks
b GivenI1= 0.25V1 0.2 V2
I2 0.2V1 0.1 V2 Find T parameters
4 marks
c The unbalanced three phase 4 wire star connected load impedance shown in
the fig.10(c) is supplied by a balanced 400 V three phase 50Hz supply.Phase
sequence is RYB. Determine the voltage at the star point of the load with
respect to supply neutral. Also determine the line currents.
Fig
8 marks