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Reg No.:_ Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
FIFTH SEMESTER B.TECH DEGREE EXAMINATION(R&S), DECEMBER 2019
Course Code: EE311
Course Name: ELECTRICAL DRIVES & CONTROL FOR AUTOMATION
Max. Marks: 100 Duration: 3 Hours

PARTA
Answer any three full questions, each carries 10 marks. Marks
1 ஐ Explain how the OCC of a ‏عل‎ shunt generator is obtained. Define critical (6)

resistance and critical speed.

b) List out the applications of de generator (4)

2 93) What are the various losses occurring in ೩ de generator (4)
b) Ina 120۷ compound generator, the resistance of the armature, shunt and series (3)
windings are 0.06Q, 25 Q and 0.04 Q respectively. The load current is 100 A at
120V.Find the induced emf and armature current when the machine is connected
as long shunt
c) What 15 mean by armature reaction? What are its effects on main field flux (3)
3 9) Explain how the speed is related to flux and back emf for a series and shunt (4)
motor
b) With the help of block diagram explain the power stages of 60 motor (4)
€) A 250 V shunt motor on no load runs at 1000 rpm and takes 5 amperes (2)
.Armature and shunt field resistances are 0.2 and 250 Q respectively. Calculate

the speed when loaded taking a current of 50 A. The armature reaction weakens

the field by 3%
4 9) Explain the working of a 3 point starter (6)
b) Explain the procedure for determining the efficiency of a dc motor (4)

PARTB
Answer any three full questions, each carries 10 marks.
5 9) _ Derive the EMF equation of a transformer (4)
b) Explain the vector diagram of transformer under no load (6)

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