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E192023 Pages:2

Draw and explain Instruments transformers
Define voltage regulation of a transformer
With a diagram explain the working principle of a 3 phase induction motor
Draw the equivalent circuit of three phase induction motor
A 3 phase Induction motor is wound for a 4 poles and is supplied from 50 Hz
system calculate i) synchronous speed ii) speed of the rotor when the slip is 4%
Explain the no load and blocked rotor test of a 3 phase induction motor
A 4 pole 50 Hz 3phase induction motor has a rotor resistance of 0.024 Q/ph and
standstill reactance of 0.6 Q/ph. Determine the speed at which maximum torque
is developed
PART C

Answer any four full questions, each carries 10 marks.

Explain the working of a universal motor?

Explain the constructional details of alternator

Derive emf equation of an alternator

Define voltage regulation of an alternator

Explain the different starting methods of synchronous motor

Find the number of armature conductors in series per phase required for the
armature of a 3 phase , 50 Hz ,10 pole alternator . The winding is star connected
to give a line voltage of 11 kV. The flux /pole is 0.16 Wb. Assume 14.51 and
Ka=0.96

Explain with figure the working of multistack variable reluctance stepper motor
List out the advantages of variable reluctance motor

With the help of neat diagram explain the working of hybrid stepper motor
Draw and explain the torque speed characteristics of stepper motor

List out the applications of stepper motors

With block diagram explain programmable logic controllers

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