Which of the following statements related to the speed control of DC shunt and series motors is correct?
1
In series-parallel control, the motors are joined in parallel at lower speeds and series at higher speeds.
2
In the Rheostatic control methods of shunt motors, the series resistor must be connected between the line and the motor.
3
Field diverters and tapped field control methods are mostly used in DC shunt motors.
4
In a tapped field control when all the field turns are present in the circuit, the motor runs at the lowest speed.