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Subject Code: KEE061
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BTECH
(SEM VI) THEORY EXAMINATION 2021-22
SPECIAL ELECTRICAL MACHINES
Time: 3 Hours Total Marks: 100
Note: Attempt all Sections. If you require any missing data, then choose suitably.
SECTION A
1. Attempt all questions in brief. 2*10 = 20
Qno Questions CO
(a) How stepper motors are different from conventional motors. 1
(b) Give the advantage of having low rotor inertia of two phase ac 1
servomotor.
(c) What is stepper motor? State its type. 2
(d) Define step angle. 2
(e) Give the classification of switched reluctance motors. 3
(f) State any four applications of switched reluctance motors 3
(g) What are the types of permanent magnet DC motor 4
(h) Write any four applications of PCB motors. 4
(i) Write any four applications of hysteresis motors. 5
(j) Write any four applications of reluctance motors. 5
29
98
_0
9.
SECTION B
P1
24
2. Attempt any three of the following: 10*3 = 30
Qno Questions CO
1.
2E
(a) Explain with the help of suitable example and sketches for the 1
.2
P2
followings
25
(i) Constant torque control of Induction Machine
Q
|1
(ii) Constant power control of Induction Machine
(b) Explain the construction and principle of operation of hybrid stepper 2
34
motor.
2:
(c) Explain the principal of operation and operating modes of switched 3
:3
reluctance motor. Also writes its advantage and disadvantage.
13
(d) Explain the principal of operation and torque production of three-phase 4
2
three-pulse brushless dc motor. Also mention its advantage over
02
conventional dc motor.
-2
(e) Write short note on 5
(i) Hysteresis motor
06
(ii) Single phase reluctance motor
5-
|1
SECTION C
3. Attempt any one part of the following: 10*1 = 10
Qno Questions CO
(a) Write short note on two phase servomotor discussing the construction, 1
torque-speed characteristics and applications.
(b) Write short note on the followings- 1
(i) Characteristics of SEIG in detail.
(ii) Characteristics of DFIG in detail
QP22EP1_029 | 15-06-2022 13:32:34 | 125.21.249.98
Printed Page: 2 of 2
Subject Code: KEE061
0Roll No: 0 0 0 0 0 0 0 0 0 0 0 0 0
BTECH
(SEM VI) THEORY EXAMINATION 2021-22
SPECIAL ELECTRICAL MACHINES
4. Attempt any one part of the following: 10 *1 = 10
Qno Questions CO
(a) Write short note on permanent magnet stepper motor discussing its 2
construction, operation and application.
(b) Discuss in details the principle of operation and characteristics of 2
hybrid stepper motor with applications.
5. Attempt any one part of the following: 10*1 = 10
Qno Questions CO
(a) Discuss various drive circuits of switched reluctance motors 3
(b) Explain in details the constructional features of Linear SRM. Also 3
discuss the principle of operation, Torque production and performance
characteristics.
6. Attempt any one part of the following: 10*1 = 10
Qno Questions CO
(a) Write short note on permanent magnet synchronous generators and 4
29
their applications.
98
(b) Write short note on the followings- 4
_0
9.
(a) Sinusoidal PM ac motors.
P1
24
(b) Brushless DC motors.
1.
2E
7. Attempt any one part of the following: 10*1 = 10
.2
P2
Qno Questions CO
25
(a) A universal series motor when operating on 220 V dc, draws 10 Amp 5
Q
|1
and runs at 1440 r.p.m. Find the new speed and p.f. when connected to
220 V 25 Hz ac supply, the motor current remaining the same. The
34
motor has total resistance of 1 Ω and total inductance of 0.1H.
2:
(b) An ac operated universal motor has a 2-pole armature with 960 5
:3
conductors. At a certain load the motor speed is 5000 rpm and the
13
armature current is 4.6 Amp; the armature terminal voltage and input
are respectively 100 V and 300 W. Calculate the following quantities
2
assuming an armature resistance of 3.5 Ohm.
02
(i) Effective armature reactance
-2
(ii) Maximum value of useful flux/pole.
06
5-
|1
QP22EP1_029 | 15-06-2022 13:32:34 | 125.21.249.98
