Question

Choose the correct answer for each question and explain why its right.

1. If it is necessary to reverse the direction of a DC motor, the simplest way to do it is to a. reverse the armature leads b. reverse the polarity of the power supply leads c. add a capacitor between the positive and negative DC voltage leads d. get a reversed wired DC motor In a shunt configured DC motor, the series field is a. attached in series with the shunt field of the motor b. connected in parallel to the shunt field of the motor C. disconnected from the motor d. shorted out (shunted) to prevent counter EME 3. In a series configured DC motor, the series field is a. attached in series with the armature of the motor b. attached in series with the shunt field of the motor C. connected in parallel to the shunt field of the motor d. connected in parallel with the shunt field and in series with the armature 4. In a series configured DC motor, the speed is adjusted by varying the a. load resistance b. source voltage C. temperature coefficient d. thermal dynamic pressure 5. Care should be taken to make sure that the shunt coil is not disconnected when the motor is running or will happen. a. the motor will overheat b. the motor will stop C. the motor will run away d. the motor will melt