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Worksheets141 S13 DC Motors 2
Total questions: 30
Worksheet time: 3hrs 30mins
Name
Class
Date
1.
What is the function of the commutator in a DC motor?
a)
A) To provide one of the magnetic fields
b)
B) To rotate the armature
c)
C) To reverse the direction of current
d)
D) To generate electrical energy
2.
What material are the brushes of a DC motor made of?
a)
A) Copper
b)
B) Aluminum
c)
C) Carbon
d)
D) Iron
3.
Why are carbon brushes used in a DC motor?
a)
A) Because they are hard
b)
B) Because they are an insulator
c)
C) Because they are a conductor
d)
D) Because they overheat easily
4.
What is the function of the armature windings in a DC motor?
a)
A) To provide one of the magnetic fields
b)
B) To generate electrical energy
c)
C) To rotate and provide mechanical energy
d)
D) To connect to the commutator
5.
What is the purpose of the segments and insulators in the commutator of a DC motor?
a)
A) To provide one of the magnetic fields
b)
B) To rotate the armature
c)
C) To reverse the direction of current
d)
D) To generate electrical energy
6.
How is the connection to the load made in a DC motor?
a)
A) Through the commutator
b)
B) Through the brushes
c)
C) Through the field windings
d)
D) Through the rotor
7.
What happens when the armature coil in a DC motor moves through the plane perpendicular to the magnetic field?
a)
A) The torque on the motor reverses its direction
b)
B) The armature generates electrical energy
c)
C) The commutator reverses the direction of current
d)
D) The brushes become worn down
8.
What is the purpose of the load in a DC motor?
a)
A) To generate electrical energy
b)
B) To provide a magnetic field
c)
C) To provide a mechanical load for the motor to work against
d)
D) To connect to the field windings
9.
What type of supply is produced as the armature windings rotate within the magnetic field of a DC motor?
a)
A) A DC supply
b)
B) An AC supply
c)
C) A mechanical supply
d)
D) A hydraulic supply
10.
What is the purpose of the carbon brushes in a DC motor?
a)
A) To provide a mechanical load
b)
B) To generate electrical energy
c)
C) To connect to the load
d)
D) To supply current to the armature
11.
What is the basic principle of operation of any electrical machine whether DC or AC?
a)
A. Conversion of mechanical energy into electrical energy
b)
B. Conversion of electrical energy into mechanical energy
c)
C. Conversion of heat energy into mechanical energy
d)
D. Conversion of light energy into electrical energy
12.
What are the machines called that convert electrical energy into useable rotational motion?
a)
A. Generators
b)
B. Transformers
c)
C. Motors
d)
D. Conductors
13.
What is the device that rotates within a standard DC motor?
a)
A. Field
b)
B. Commutator
c)
C. Armature
d)
D. Yoke
14.
What part of a DC motor is sometimes referred to as a stator or yoke?
a)
A. Armature
b)
B. Field
c)
C. Commutator
d)
D. Brushes
15.
What do the field windings of a DC motor provide?
a)
A. Electrical energy
b)
B. Mechanical energy
c)
C. Magnetic fields
d)
D. Heat energy
16.
Which part of a DC motor has windings that start and finish at a point called the commutator?
a)
A. Field
b)
B. Armature
c)
C. Yoke
d)
D. Brushes
17.
What are the brushes on a DC motor made of?
a)
A. Steel
b)
B. Copper
c)
C. Aluminum
d)
D. Carbon
18.
What is the purpose of the commutator in a DC motor?
a)
A. To reverse the direction of current
b)
B. To increase the speed of the motor
c)
C. To decrease the voltage
d)
D. To lubricate the moving parts
19.
Which type of DC motor lacks good speed regulation but is well-suited for high-torque loads?
a)
A. Series-wound
b)
B. Shunt-wound
c)
C. Compound-wound
d)
D. None of the above
20.
What connects the field windings in a series-wound DC motor?
a)
A. In parallel
b)
B. In series
c)
C. In parallel and series
d)
D. None of the above
21.
How are the field coils and the armature coil connected in a series-wound DC motor?
a)
A. In parallel
b)
B. In series
c)
C. In parallel and series
d)
D. None of the above
22.
Which type of DC motor uses high-resistance field windings connected in parallel with the armature windings?
a)
A. Series-wound
b)
B. Shunt-wound
c)
C. Compound-wound
d)
D. Both A and C
23.
How is the field coil connected in a shunt-wound DC motor?
a)
A. In series with the armature
b)
B. In parallel with the armature
c)
C. In series and parallel with the armature
d)
D. None of the above
24.
What type of DC motor runs at constant speed, regardless of the load?
a)
A. Series-wound
b)
B. Shunt-wound
c)
C. Compound-wound
d)
D. Both A and C
25.
How is the speed of shunt-wound motors regulated?
a)
A. By inserting resistance in series with the armature
b)
B. By inserting resistance in the field circuit
c)
C. By changing the supply voltage
d)
D. Both A and B
26.
What is the advantage of compound-wound motors?
a)
A. Ability to start up against heavy loads
b)
B. Constant speed as the load varies
c)
C. Both A and B
d)
D. None of the above
27.
How many major classifications of DC compound-wound motors are there?
a)
A. One
b)
B. Two
c)
C. Three
d)
D. Four
28.
What are the three major classifications of DC compound-wound motors?
a)
A. Series, Shunt, Compound
b)
B. Cumulative, Differential, Compound
c)
C. Parallel, Series, Compound
d)
D. None of the above
29.
Which type of compound-wound motor combines the advantages of both series-wound and shunt-wound motors?
a)
A. Cumulative
b)
B. Differential
c)
C. Compound
d)
D. None of the above
30.
What is connected in series with the armature in a compound-wound motor?
a)
A. Field winding
b)
B. Commutator
c)
C. Brushes
d)
D. None of the above
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