Electrical Machines
The synchronous motor can be started by

  providing damper winding in its rotor circuit.
  coupling it with a small AC induction motor called the pony motor.
  coupling it with a DC compound motor.
  any of the above methods.

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Electrical Machines
Ward-Leonard system for controlling the speed of a DC motor is used where

 All of above.
 The speed in both the direction is required.
 The accuracy in speed control is required.
 Very fine speed control over the whole range from zero to normal speed is required.

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