Hall Ticket No Question Paper Code: AEE017
INSTITUTE OF AERONAUTICAL ENGINEERING
(Autonomous)
B.Tech III Semester End Examinations (Regular) December, 2017
Regulation: IARE R16
ELECTRICAL TECHNOLOGY
(Electronics and Communication Engineering)
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 Transient response of an series RL circuit using differential equations approach.
Determine the current equations for i1 and i2 for the circuit given in Figure1 when the switch is
closed at t=0.
Figure 1
2. Explain the Transient response of an series RC circuit using differential equations approach.

In the circuit shown in Figure 2 determine the current when the switch is moved from position
1 to 2 at time t=0 using Laplace transform.
Figure 2
UNIT II
3. Explain the hybrid parameters of a two port network.
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.
Page 1 of 2
4. Discuss the interconnection of two port networks.
Find out the ABCD parameters of the network shown in the Figure 3. Also find the image
parameters for the network.
Figure 3
UNIT III
5. Explain any two types of attenuators.
Design a constant high pass (both section and T section) filter having a cut off frequency of
1 kHz to operate with a load resistance of 600 ohm.
6. Describe design equations of band pass filters.
Design a type attenuator to have characteristic impedance of 100 ohm and attenuation of 20
dB.

UNIT IV
7. Derive the armature torque expression of a dc motor.
A 250V shunt motor runs at 1000rpm at no load and takes 8A. The total armature and shunt
field resistances are 0.2 ohm and 250 ohm respectively. Calculate the speed when loaded and
taking 50A. Assume the flux to be constant.
8. What are the different types of speed control methods in DC motors? And explain the field
control method.
A 240 4-pole shunt motor has N 1000 rpm, output 15 HP, Ia 50 Ra 0.1

Ish 1A. Brush drop 1V/brush, winding wave, Z 540. Find useful torque, total torque, and
useful flux per pole, rotational losses and efficiency.
UNIT V
9. Explain the various losses in a transformer. How these losses are minimized?
In a 25 KVA, 2000/200V transformer the iron and copper losses are 350 Watts and 400 Watts
respectively. Calculate the efficiency at full load and 0.8 power factor lagging.
10. Explain the constructional details and working principle of transformer with neat sketch.
A single phase, 2850/500V transformer gave the following results:
Open Circuit test: 250V, 1A, 80W (LV side)
Short circuit test: 20V, 12A, 100W (HV side)
Draw the equivalent circuit by showing all the circuit constants.