Electrical Machines II

Give the importance of airgap in rotating machines.

Give application of winding distribution factor.

What is pulsating magnetic field?

Give application of Doubly-Fed Induction Machines.

Give application of Single Phase Induction Motor.

What information can be obtained from a V curve?

What type of winding is an important factor in rotating machines?

Give basic difference between torque and speed of a rotating machine.

What information can be obtained from a phasor diagram?

Give challenges related to cylindrical rotor synchronous machine.

Give scope and outcome of this course?

Explain the following : (a) Distributed winding (b) Winding axis

By help of suitable diagram, explain the concept of Magnetic field produced by a single winding.

Explain the effect of parameter variation on torque-speed characteristics for an Induction motor.

Explain the Split-phase starting methods.

A 3-phase, 16-pole synchronous generator has a star-connected winding with 144 slots and 10 conductors per slot. The flux per pole is $0.04\text{ Wb}$ and the speed is $375\text{ rpm}$. Find the frequency and phase emf and line emf. The total turns/phase may be assumed to be series connected.

Explain the concept of power-angle characteristics.

Explain the construction and working of a squirrel cage induction motor with its torque slip characteristics.

Find the synchronous impedance, synchronous reactance and the terminal voltage when full load is thrown off, Of a $250\text{ Amp}$, $6600\text{ Volts}$, $0.8\text{ p.f.}$ alternator, in which a given field current produces an armature current of $250\text{ Amp}$ on short circuit and a generated e.m.f. of $1500\text{ Volts}$ on open circuit. The armature resistance is $2\Omega$.

Explain working method of parallel operation of alternator.

Explain the concept of Three windings spatially shifted by 120 degrees by help of suitable application.

Write short notes on any two from the following : (a) Sinusoidally distributed winding (b) Braking and speed control for induction motors (c) Starting of a Synchronous motor