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Why a generator slow down with resistive loading?

  1. May 30, 2007 #1
    anyone here know why a generator slow down with resistive loading ?

    i did an experiment and my results showed that when i loaded the generator more and more the frequency dropped from 50Hz to about 47Hz
    (power factor was unity all the time)
  2. jcsd
  3. May 30, 2007 #2


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    Gold Member

    Consider the induced current in the coil as a result of the turning of the armature. [Read up on the motor effect]. This current experiences a force that is opposite in direction to the motion that induced the current. So this means that when we add a load, more has to be supplied; more current in the coil; a stronger force acts on the rotor but in a direction that opposes the original motion; thus its harder for the motor to turn.
  4. May 31, 2007 #3
    but why this doesnt happen when you load using capacitive or inductive loads?
  5. Jun 2, 2007 #4
    because capacitative and inductive loads don't have resistance, only reactance, they don't dissipate power
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