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RICH DAD POOR DAD BOOK REVIEW

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  RICH  DAD  POOR  DAD  BOOK REVIEW This is amazing book.   • Explodes the myth that you need to earn a high income to become rich • Challenges the belief that your house is an asset • Shows parents why they can't rely on the school system to teach their kids about money • Defines once and for all an asset and a liability • Teaches you what to teach your kids about money for their future financial success It's been nearly 25 years since Robert Kiyosaki’s  Rich Dad Poor Dad  first made waves in the Personal Finance arena. It has since become the #1 Personal Finance book of all time... translated into dozens of languages and sold around the world. Rich Dad Poor Dad  is Robert's story of growing up with two dads — his real father and the father of his best friend, his rich dad — and the ways in which both men shaped his thoughts about money and investing. The book explodes the myth that you need to earn a high income to be rich and explains...
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Methods of Reducing Armature Reaction

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Methods of Reducing Armature Reaction :-

  • If the brushes are left on GNA, then emf collected would reduce and coil undergoing commutation would no longer have zero rotational voltage leading to serious commutation problems. The immediate solution therefore, appears to shift the brushes in the new MNA.
  • The brush shift results into improved commutation but reduce thus resultant flux resulting into reduction in emf in generator action and increase in speed in motor action.
  • Far ( demagnetizing ) = {(Z/2) / P} * {(2ꞵelect) / 180°} * {Ia / A}

  • Brush shift has serious limitations. Since, shift in MNA is proportional to Armature current the brush has to be shifted in a new position every time the load changes, direction of rotation changes or mode of operation changes.
  • Therefore, brush shift is limited to various small machines and there too the brushes are fixed at a position corresponding to expected load, direction of rotation and mode of operation.
  • In practice the brushes are moved slightly further to counter the effect of reactance voltage that would further improve commutation.
  • Brushes are shifted in direction of rotation for a generator and opposite to direction of rotation of a motor.
  • In large machines, inter poles also called commutating poles are used to overcome commutation problems.
  • Armature reaction waveforms are shown below :



  • Armature MMF from the above figure is triangular in shape and due to large air gap along q-axis the armature flux density is reduced along q-axis.
  • The point where total flux density is zero is defined as Magnetic Neutral Axis and where flux density due to poles is zero is defined as Geometric Neutral Axis. From above figure due to Armature Reaction there is a shift between the two.

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