Physics-
General
Easy

Question

A six pole generator with fixed field excitation developes an emf of 100 V, when operating at 1500 rpm. At what speed must it rotate to develop 120 V?

  1. 1200 rpm  
  2. 1800 rpm  
  3. 1500 rpm  
  4. 400 rpm  

The correct answer is: 1800 rpm


    The emf induced is directly proportional to rate at which flux is intercepted which varies directly as the speed of rotation of the generator.
    New, speed=fraction numerator 120 over denominator 100 end fraction cross times 1500 blank r p m equals 1800 blank r p m

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