For the same power output rating and full load speed, the motor will have poorest starting torque, is
A. Series.
B. Shunt.
C. Differential compound.
D. Cummulative compound.
Answer: B
Share your understanding of this question with the correct explanation.
For the same power output rating and full load speed, the motor that will have the poorest starting torque is a Shunt motor.
Shunt motors are a type of DC motor that have the field winding connected in parallel (shunt) with the armature winding. These motors typically have good speed regulation and a relatively constant speed throughout the load range.
However, when it comes to starting torque, shunt motors have poorer performance compared to other types of DC motors. The starting torque of a motor is the torque it can generate when starting from rest.
In a shunt motor, the field winding and armature winding are connected in parallel, which means that the field current remains constant during starting. This design configuration limits the ability of the shunt motor to produce high starting torque.
On the other hand, series motors and compound motors (both differential and cumulative) have higher starting torque capabilities. Series motors have a higher starting torque due to the high starting current flowing through both the field winding and the armature winding. Compound motors, especially cumulative compound motors, provide additional starting torque due to the additive effect of the series and shunt fields.
Therefore, the correct answer is B: Shunt motor. A shunt motor will have the poorest starting torque compared to the other options given.