Hall Ticket No Question Paper Code: AEE017
INSTITUTE OF AERONAUTICAL ENGINEERING
(Autonomous)
Four Year B.Tech III Semester End Examinations (Supplementary) July, 2018
Regulation: IARE R16
ELECTRICAL TECHNOLOGY
Time: 3 Hours Max Marks: 70
Answer ONE Question from each Unit
All Questions Carry Equal Marks
All parts of the question must be answered in one place only
UNIT I
1. Explain the DC transient response of an series RLC circuit.
For the circuit shown in Figure 1 find the current equation when the switch is changed from
position 1 to position 2 at t=0 using differential equation approach.
Figure 1
2. Explain the DC transient response of an series RL circuit.
For the circuit shown in Figure 2 obtain the equations for and when the switch is
closed at t=0 using Laplace transformation method.
Figure 2
UNIT II
Page 1 of 3
3. Explain the cascaded and parallel configurations of two port networks.
Find the Z parameters for the circuit shown in Figure 3
Figure 3
4. Explain hybrid parameters with necessary equations.
The Z parameters of a two port network are z11=6ohm, z22=4 ohm, z12=z21=3 ohm. Find the
equivalent Y parameters and ABCD parameters.
UNIT III
5. Derive he expression for characteristic impedance and design equations of type attenuator.

Design a symmetrical lattice attenuator to have characteristic impedance of 800 ohm and attenuation
of 20dB.

6. Derive the characteristic impedance and cutoff frequency of band pass and band rejection filters.

Design a constant low pass (both section and T section) filter having a cut off frequency of
2 kHz to operate with a terminated load resistance of 500 ohm.
UNIT IV
7. Derive the expression for EMF equation of the DC generator.
A 20KW, 440 volt short shunt compound wound DC generator has armature, shunt, and series
field resistances are 0.4 ohm, 240 ohm and 0.25 ohm respectively. The losses are 75W.Calculate
the full load efficiency of the generator.
8. What are the different types of speed control methods in DC motors? Explain the field control
method.
A 230 volts DC motor drives a load at certain speed and take a current of 45A. The load
characteristics are such that its torque is proportional to its cube of the speed. It is decided
to reduce the speed of motor to 80% of its initial value by adding external resistance in series
with armature winding. Calculated the value of this resistance. The total armature resistance of
motor is 1 ohm.
Page 2 of 3
UNIT V
9. Draw and explain the phasor diagram of the transformer at no-load and on-load conditions.

A 200KVA, single phase transformer has an efficiency of 98% at full load. The maximum efficiency
occurs at 3/4th full load. Calculate:
i. The iron losses
ii. The copper losses at full load
iii. The efficiency at half load assuming a power factor of 0.8 at all loads.
10. Draw and explain the approximate equivalent circuit of a transformer with reference to the
primary side.
A single phase transformer has 400 primary and 100 secondary turns. The net cross sectional
area of the core is 60 cm2. If the primary winding is connected to a 50 Hz supply at 520 Volts.
Calculate:
i. The peak value of flux density in the core
ii. Voltage induced in the secondary winding
iii. Transformation ratio
iv. EMF induced per turn in both the windings