ALWARDAS POLYTECHNIC
UNIT-I -EE-502 BOARD DIPLOMA EXAMINATIONS, (C-20)
DEEE–VIth SEMESTER EXAMINATION– ELECTRICAL MACHINES-III
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DURATION: 90MNTS
PART-A
MARKS: 40
(1X4+4X3=16)
ANSWER ALL QUESTIONS
1. (a) Speed of rotating magnetic field depends on
a. No of poles
b. Frequency c. Supply voltage d. Both a & b only e. all of the above
(b) Rotor frequency is equal to
a. Poles X supply frequency b. slip X supply frequency
c. voltage X supply frequency d. None of the above
(c) Universal motor runs speed of at no load a.1500rpm b. 3000rpm c.1000rpm d. around
12000rpm
(d) The full load slip of I.M is about a) 10 to 20% b) 20 to 30% c) 2 to 5% d) none of the above
2. List applications of 3-phasse induction motor
3. State the necessity of starter in 3-phase induction motor and give its types.
4. Draw the torque- slip characteristics of 3-phase induction motor.
5. Classify 1-phase induction motors.
PART-B
ANSWER ALL QUESTIONS
6. (a) Explain the principal of operation of 3Ø induction motor.
(OR)
(b)Explain construction and working of DOL starter for induction motor.
7. (a) Explain working of single phase split phase type induction motor with neat diagram.
(OR)
(b)Explain working of single phase shaded pole type induction motor with neat diagram.
8. (a) Explain why single phase induction motor is not a self starting machine.
(OR)
(b) Explain procedure of circle diagram with neat diagram.
3X8=24
ALWARDAS POLYTECHNIC
UNIT-I -EE-502 BOARD DIPLOMA EXAMINATIONS, (C-20)
DEEE–VIth SEMESTER EXAMINATION– ELECTRICAL MACHINES-III
--------------------------------------------------------------------------------------------------------------------------------------
DURATION: 90MNTS
PART-A
MARKS: 40
(1X4+4X3=16)
ANSWER ALL QUESTIONS
1. (a) Speed of rotating magnetic field depends on
a. No of poles
b. Frequency c. Supply voltage d. Both a & b only e. all of the above
(b) Rotor frequency is equal to
a. Poles X supply frequency b. slip X supply frequency
c. voltage X supply frequency d. None of the above
(c) Universal motor runs speed of at no load a.1500rpm b. 3000rpm c.1000rpm d. around
12000rpm
(d) The full load slip of I.M is about a) 10 to 20% b) 20 to 30% c) 2 to 5% d) none of the above
2. List applications of 3-phasse induction motor
3. State the necessity of starter in 3-phase induction motor and give its types.
4. Draw the torque- slip characteristics of 3-phase induction motor.
5. Classify 1-phase induction motors.
PART-B
ANSWER ALL QUESTIONS
6. (a) Explain the principal of operation of 3Ø induction motor.
(OR)
(b)Explain construction and working of DOL starter for induction motor.
7. (a) Explain working of single phase split phase type induction motor with neat diagram.
(OR)
(b)Explain working of single phase shaded pole type induction motor with neat diagram.
8. (a) Explain why single phase induction motor is not a self starting machine.
(OR)
(b) Explain procedure of circle diagram with neat diagram.
3X8=24