Electrical Machines Questions and Answers
Rotating Magnetic Field – 2
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Which of the following harmonics are present in the resultant MMF produced by 3 phase currents flowing in the 3 phase windings?
Correct!
Wrong!

When a singlephase winding is excited by an alternating current, then which of the following statements are correct?
Correct!
Wrong!

The rotating MMF wave of constant amplitude can be produced, only if the time angle displacement between currents is ____________
Correct!
Wrong!

If F_{1} is the constant amplitude of fundamental rotating MMF wave, the for the space harmonics of order 6K1 (where K=1,2,3….), the harmonic MMF wave is of _________
Correct!
Wrong!

Three phase voltages are applied to the three windings of an electrical machine. If any two supply terminals are interchanged, then the rotating MMF wave _______
Correct!
Wrong!

What does the space angle α in the equation F_{r}(α,t)=3/2F_{m}cos(αωt) for MMF produced when 3phase balanced windings excited by three phase balanced currents represent?
Correct!
Wrong!

In case of the 3 phase winding with delta or star connection without neutral, if one of the supply lines gets disconnected, then the MMF becomes _______
Correct!
Wrong!

A 3 phase star connected winding is fed from symmetrical 3 phase supply with their neutrals connected together. If one of the 3 supply lines gets disconnected, then the revolving MMF wave will have a __________
Correct!
Wrong!

If φ_{m} is the maximum value of flux due to any one phase, then resultant flux in 2 phase and 3 phase AC machines would respectively be given by ______
Correct!
Wrong!
