Deck 16: Dc Motors and Sequence Control

Question 1

The speed of a DC motor can be controlled by applying variable voltage to the armature or field.

Answer 1

True

Question 2

When a motor is connected as a cumulative compound, the shunt and series fields are connected in such a manner that as current flows through the windings, they aid each other in the production of magnetism.

Answer 2

True

Question 3

____, which press against the commutator segment, supply power to the armature from the DC power line.

A) Windings
B) Resistors
C) Shunts
D) Carbon brushes

Answer 3

Carbon brushes

Question 4

There are three basic types of DC motors: the series, the shunt, and the ____.

A) compound
B) winding
C) armature
D) differential

Question 5

The ____________________ is the rotating part of the motor.

Question 6

There are two types of field windings used in DC motors: series and ____________________.

Question 7

What are some applications of DC motors?

Question 8

How do you reverse a compound motor?

Question 9

Auxiliary contacts on motor starters cannot be used to control the action of timed relays.

Question 10

Some circuits employ the use of normally open auxiliary contacts to prevent motor 2 from starting before motor 1, and motor 3 cannot start before motor2. These normally open auxiliary contacts that control the starting sequence are often called ____ contacts.

A) automatic
B) permissive
C) energizing
D) overload

Question 11

Some circuit requirements may demand that the motors turn off in sequence instead of turning on in sequence. This circuit will require the use of ____ timers.

A) on-delay
B) level
C) automatic
D) off-delay

Question 12

One of the most common methods of automatic sequence control is time ____________________.

Question 13

What types of machines use sequence control?

Question 14

How do automatic sequence control circuits determine when the next motor should start?