Correct Answer - Option 2 : Reduces the voltage around the armature coils
Distributed and short pitch winding:
For obtaining smooth sinusoidal emf wave from, conductors are placed is several slots under a single pole. This armature winding is known as distributed winding.
\(E = 4.44\ {k_c}{k_d}\phi fT\)
\({k_c}\) and \({k_d}\) are always less than 1.
Distributed winding eliminates higher-order harmonics and short chording can eliminate lower harmonics (ex: 5th and 7th harmonics can be eliminated by short chording)
Advantages:
- It also reduces harmonic emf and so waveform is improved.
- It also diminishes the armature reaction.
- Even distribution of conductors helps for better cooling.
- The core is fully utilized as the conductors are distributed over the slots on the armature periphery.
Short pitch winding improves the waveform of generated emf i.e. generated emf can be made to approximate to a sine wave more easily and the distorting harmonics can be reduced or totally eliminated.
Disadvantages:
The disadvantage of using short-pitch winding is that the total voltage around the coils is somewhat reduced. In order to compensate for this reduction in Generated EMF, more number of turns, and therefore more copper is required.