Power Engineering 3A2 Review Questions With Complete Solutions

Power Engineering 3A2 Review Questions With Complete
Solutions


. The three-point starter for DC motors has connections for:
1. Line
2. Positive
3. Negative
4. Field
5. Armature
a.
1, 2, 3, 4
b.
2, 3, 4, 5
c.
1, 3, 4, 5
d.
1, 2, 3
e.
1, 4, 5
E
Where approximate constant speed is to be maintained between
no-load and full-load the DC motor to use would be:

,a.
Series
b.
Shunt
c.
Compound
d.
Separately-excited
e.
Self-excited
B
Where a large starting torque is of prime importance the DC
motor to use would be:
a.
Series
b.
Long-shunt
c.
Short-shunt
d.
Compound
e.
Cumulative compound
A
As the flux of a shunt motor remains constant its torque is:
a.
Inversely proportional to armature current

,b.
Proportional to armature current
c.
Increased
d.
Decreased
e.
Unchanged
B
The voltage drop at the armature of a shunt DC motor is a
percentage that normally does not exceed:
a.
0.05 %
b.
0.5 %
c.
0.9 %
d.
5.0 %
e.
50 %
D
The most common type of industrial electrical generation is:
a.
Single phase
b.
Two phase

, c.
Three phase
d.
DC generators
e.
AC motors
C
When you are synchronizing an electrical generator and the
synchronizing lamps are dark, you:
a.
Should have higher voltage ratings than the line system
b.
Have lower voltage rating
c.
Have two or more lamps connected in parallel
d.
Should have colored glass
e.
Should have higher current ratings than the line system
A
Modern alternators consist of a rotor on which the AC voltage
producing windings are placed and a rotating stator on which a
DC excitation winding is placed.
a. True

b. False
B