Deck 1: The DC Shunt Motor

Question 1

To reverse the direction of the armature rotation of a DC motor, the current direction in both the field and the armature must be reversed.

Answer 1

False

Question 2

A(n) ____________________ has the field circuit connected in parallel with the armature.

Answer 2

shunt motor

Question 3

By using the ____________________ rule for motors, one can determine which direction a current-carrying conductor will move when placed in a magnetic field.

Answer 3

right-hand
right hand

Question 4

As a DC motor armature starts to rotate, the CEMF increases and the line current decreases.

Question 5

What two factors are important when selecting a motor for a particular application?

Question 6

The rotating force at the motor shaft produced by the interaction of the magnetic fields of the armature and the field poles is called ____________________.

Question 7

The ____________________, caused by the stator magnetic field being distorted, or altered, in reaction to the armature magnetic field, is actually a bending of the motor magnetic field so that the brushes are no longer aligned with the neutral magnetic plane of the motor.

Question 8

Because torque depends on the strength of the magnetic field of the armature, which, in turn, depends on the armature current, any increase in mechanical load requires an increase in the armature current, more load, slower speed, higher differential, and more current.

Question 9

What are the two main parts of a DC motor?

Question 10

The ____________________ of a motor is a cylindrical iron structure mounted directly on the motor shaft. In DC motors, it is the rotating component of the motor.

Question 11

What is the formula for calculating torque?

Question 12

The terms speed control and speed regulation can be used interchangeably

Question 13

The magnetic polarity of the field system is arranged so that the polarity of any particular field pole is opposite to that of the poles adjacent to it.

Question 14

Name three of the four characteristics used in rating DC motors.

Question 15

Briefly describe the CEMF levels that occur with the changes in motor armature rotation.