Download AKTU B-Tech 4th Sem 2015-16 EEE 401 Electromechanical Energy Conversion I Question Paper

Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 4th Semester (Fourth Semester) 2015-16 EEE 401 Electromechanical Energy Conversion I Question Paper

Printed Pages: 4 EEE?401
(Following Paper ID and Roll No. to be ?lled in your
Answer Books)
PaperID:121405 R011N0.| I I I I I | | | |
B. TECH.
Theory Examination (Semester?IV) 2015-16
ELECTROMECHANICAL ENERGY CONVERSION?I
Time : 3 Hours Max. Marks : I00
Section-A
1. Attempt all parts. All parts carry equal marks. Write answer on
each part in short. (2X10=20)
(a) What are the basic role of ?Dummy Coils? in DC. ma-
chines ?
(b) Explain the introduction of ?electro-mechanical energy
conversion principles.?
(0) Explain the interpole and compesating Winding 0fD.C.
Machines.
(d) Explain the commutation process in DC. machines.
(e) Enlist any ?ve applications of DC. Machines.
(f) Enlist any ?ve applications of 3 phase transformers.
(g) What are the basic difference between auto?transform?
ers and 2-de transformers ?
1 (1) P.T.O.

(h)
(i)
0)
De?ne ?Phasor group of 3 phase transformers.?
De?ne open crcuit and short crcuit test of 1 phase
transformers.
Explain the all day ef?ciency of transformers.
Section-B
Attempt any 5 questions froms this section. (10X5=50)
(a)
(b)
(C)
(d)
(f)
Discuss the armature reaction of DC. machines. What
are the advantages and dis advantages of armature
reaction in DC. machines ? Explain in detail.
Write a short notes on the following :
(i) Open delta connection of 3 phase transformers.
(ii) Excitation phenomenon in 3 phase transformers.
Discuss the harmonics in 3 phase transformers. What
are the merits and demerits 0f harmonics in 3 phase
transformers.
Discuss the constructional details and working principle
of three Winding transformers. What are the limitations
and signi?cances 0f ths transformers.
Write a short notes on the parallel operations of 3 phase
transformers.
Discuss the ward Lenonard method for speed control
D.C. machines working as motoring node.
(2) P.T.O.

(g)
(h)
What do you mean by effeciency and voltage regulation
of 1 phase transformers ? Also mention the applications
and limitations of 1 phase transformers.
Write a short notes on the following :
(i) 3 phase to 2 phase connection of transforms.
(ii) 3 phase to 6 phase connection of transforms.
Section-C
Attempt any 2 questions from this section. (15X2=30)
3. Consider the equivalent circuit diagram of DC. machine as
shown in Fig-l.
Rsh= 50 Q
Fig. 1
Given data : - Brush drop = 2V / per brush
Interpole Winding drop = 0.5V
Compensating Winding drop = 0.25V
What should be the speed 0fD.C. machine working as
motoring mode ?
What should be the speed 0fD.C. machine working as
gererating mode ?
(3) P.T.O.

4. Consider the equivalent circuit diagram of 1 phase transformes
as shown in Fig 2.
L a
O??\/\/ ?\/\/
+ R le
Vt RC 2
5
Fig. 2
Given data :
R1 = 0.50 Q
1% = 0.25 Q
X1: 0.65 Q
X2 = 0.55 Q
Xm = 44 Q
RC = 440 Q
E . o
Vt ? J5 Sm (314t?45 ) Volts
(i) Determine the (?11?) primary current
(i1) Determine the (?cosGl?) primary power factor.
5. (a) Discuss the following test for DC. machines :
(i) Hopkinson?s and Swin burn?s test
(i1) D. C. resistance test.
(b) Discuss the following test on 1 phase transformers :
(i) Sumpner?s test (ii) Polarity test
1 (4) P.T.O.