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EEE :: Rectifiers and Converters

  1. When a rotor converter is started by means of a small auxiliary motor, the power of motor must be
  2. A.
    more than the dc output of converter
    B.
    more than ac input of converter
    C.
    half of dc output of converter
    D.
    slightly more than the value of friction and windage losses at rated speed

  3. A rotary converter can be started
  4. A.
    from dc side as dc motor
    B.
    from ac side as induction motor
    C.
    by means of a small auxiliary motor
    D.
    any of the above methods

  5. In a synchronous converter, the l2R losses are less as compared to dc generator of the same size because
  6. A.
    dc currents are negligible
    B.
    ac components neutralize the dc
    C.
    cyclic fluctuations have low frequency
    D.
    operating speed is low

  7. In a rotary converter l2R? losses as compared to a dc generator of the same size will be
  8. A.
    four times more
    B.
    double
    C.
    same
    D.
    less

  9. In a rotary converter
  10. A.
    armature currents are dc only
    B.
    armature currents are ac only
    C.
    partly ac and partly dc
    D.
    All of the above