CFESA ELECTRICAL FINAL EXAM WITH
QUESTIONS AND ANSWERS, GRADED A+
Line impedance starters:
Select one:
a. Is a very inexpensive method.
b. Give a lower starting torque.
c. Is a costlier method.
d. Is used only on rotating switch starters.
e. Give higher starting torque. - ✔✔✔✔-b
To take an alternator off the line in a system involving two or more
alternators, the driving torque of the prime mover of the alternator to be
removed should be reduced until it is supplying no current to the bus bars.
Select one:
True
False - ✔✔✔✔-True
Paralleling alternators require the following conditions:
1. It must be in phase with the system.
2. The incoming alternator must be the same voltage as the system.
,3. Its phase sequence must be the same as the system.
4. Alternator frequency and system frequency must be the same.
Select one:
a. 1, 2, 3
b. 2, 3, 4
c. 1, 2, 3, 4
d. 1, 2, 4
e. 1, 3, 4 - ✔✔✔✔-c
Wound rotor induction motors:
Select one:
a. Are not very reliable.
b. Require less maintenance than squirrel cage motors.
c. Are used to control speed.
d. Are more reliable.
e. Are less complicated in construction than other motors. - ✔✔✔✔-c
Three phase systems often use banks of _____ transformer to replace three-
phase transformers.
Select one:
a. Single phase.
b. Auto transformers.
c. Double phase.
d. Step up.
e. Step down. - ✔✔✔✔-a
, Modern alternators consist of a rotor on which:
Select one:
a. An AC excitation voltage is produced
b. The AC voltage producing windings are placed
c. A DC excitation winding is placed
d. An AC excitation winding is placed
e. The DC voltage producing windings are placed - ✔✔✔✔-c
Alternators:
Select one:
a. Split ring on the rotor
b. Slip rings on the stator
c. Have AC excitation on the rotor
d. Have a rotating armature on which a DC excitation winding is placed
e. DC excitation voltage on the stator - ✔✔✔✔-d
Auto-transformers:
Select one:
a. Use two windings for primary and secondary circuits.
b. Have a lower ratios of transformation.
c. Can use less copper.
d. Have large ratios of transformation.
e. Use more copper. - ✔✔✔✔-c
QUESTIONS AND ANSWERS, GRADED A+
Line impedance starters:
Select one:
a. Is a very inexpensive method.
b. Give a lower starting torque.
c. Is a costlier method.
d. Is used only on rotating switch starters.
e. Give higher starting torque. - ✔✔✔✔-b
To take an alternator off the line in a system involving two or more
alternators, the driving torque of the prime mover of the alternator to be
removed should be reduced until it is supplying no current to the bus bars.
Select one:
True
False - ✔✔✔✔-True
Paralleling alternators require the following conditions:
1. It must be in phase with the system.
2. The incoming alternator must be the same voltage as the system.
,3. Its phase sequence must be the same as the system.
4. Alternator frequency and system frequency must be the same.
Select one:
a. 1, 2, 3
b. 2, 3, 4
c. 1, 2, 3, 4
d. 1, 2, 4
e. 1, 3, 4 - ✔✔✔✔-c
Wound rotor induction motors:
Select one:
a. Are not very reliable.
b. Require less maintenance than squirrel cage motors.
c. Are used to control speed.
d. Are more reliable.
e. Are less complicated in construction than other motors. - ✔✔✔✔-c
Three phase systems often use banks of _____ transformer to replace three-
phase transformers.
Select one:
a. Single phase.
b. Auto transformers.
c. Double phase.
d. Step up.
e. Step down. - ✔✔✔✔-a
, Modern alternators consist of a rotor on which:
Select one:
a. An AC excitation voltage is produced
b. The AC voltage producing windings are placed
c. A DC excitation winding is placed
d. An AC excitation winding is placed
e. The DC voltage producing windings are placed - ✔✔✔✔-c
Alternators:
Select one:
a. Split ring on the rotor
b. Slip rings on the stator
c. Have AC excitation on the rotor
d. Have a rotating armature on which a DC excitation winding is placed
e. DC excitation voltage on the stator - ✔✔✔✔-d
Auto-transformers:
Select one:
a. Use two windings for primary and secondary circuits.
b. Have a lower ratios of transformation.
c. Can use less copper.
d. Have large ratios of transformation.
e. Use more copper. - ✔✔✔✔-c
