MECHANIC NEIEP UPDATED
VERSION(2025/2026) FINAL EXAM
QUESTIONS WITH CORRECT
ANSWERS A+ GRADED!!
1) What material should you use to seat brushes? - ANSWER ✔
Sandpaper
2) What color is a good commutator with good commutation? -
ANSWER ✔ Chocolate
3) Most common cause of commutator problems? - ANSWER ✔
Brush pressure too light
4) What is the result when a brush grades are mixed on a
commutator? - ANSWER ✔ The results are unpredictable
5) What is the synchronous speed of a three phase 30Hz 6 pole
motor? - ANSWER ✔ 600 rpm
6) A squirrel cage motor runs clockwise when connected in ACB
phase sequence. What will the motor do when connected in ABC
sequence? - ANSWER ✔ The motor will run in the
counterclockwise rotation.
7) What device is used to prevent starting wye and delta concurrently
- ANSWER ✔ Walking beam
8) What is the percent of slip for a three-phase 60Hz motor that has 6
poles and rotates at 1157RPM? - ANSWER ✔ 3.58%
,9) Synchronous speed - ANSWER ✔ The speed of the stator's
magnetic field on an induction motor
10) AC induction motors... - ANSWER ✔ uses a stator to act as
a rotating field
11) A motor that can run on both AC and DC - ANSWER ✔
Universal Motor
12) Polarized electrolytic capacitors - ANSWER ✔ Voltage
polarity must be correct
13) What happens in a circuit when the capacitor voltage equals
the source voltage? - ANSWER ✔ Current flow stops in the
circuit
14) What happens to capacitors the instant when power is
applied? - ANSWER ✔ Current is maximum
15) If a circuit has a capacitor of 5 microfarads and a source
voltage of 120 volts DC through a resistance of 200K, how long
will it take to fully charge? - ANSWER ✔ 5 seconds
16) If two capacitors in parallel have equal reactance of 40 ohms,
what is the total reactance? - ANSWER ✔ 20 ohms
17) What will be the total capacitance if two 125microfarad
capacitors are in parallel - ANSWER ✔ 250 microfarads
18) What is the unit of inductance? - ANSWER ✔ Henry
,19) What effect does CEMF have in an inductive circuit? -
ANSWER ✔ It is an opposing force to the applied voltage which
resists changes in circuit current
20) At what point is CEMF greatest in an inductive circuit? -
ANSWER ✔ When the rate of change for current is maximum
21) In a 100 volt 60Hz circuit, what is the total reactance with a 4
Henry inductor in the circuit? - ANSWER ✔ 1507 ohms
22) When using a megger to check insulation resistance to
ground, what is an acceptable minimum resistance? - ANSWER ✔
1 M ohm
23) What are the terminal designation of the diode? - ANSWER
✔ Anode and cathode
24) What is the voltage drop across a silicon diode that is forward
biased? - ANSWER ✔ 0.7 volts
25) What type of rectifier uses four diodes to convert the AC to
DC? - ANSWER ✔ Full wave bridge
26) Zener Diodes - ANSWER ✔ Designed to operate in reverse
bias mode
27) Varistors - ANSWER ✔ Used to prevent component
damage from surges
28) What are the common uses of transistors? - ANSWER ✔
Switching and amplification
, 29) The base and emmiter must be ___ biased in an NPN
transistor. - ANSWER ✔ Forward Biased
30) A .7 V drop from ___-__-___ is an indication of a good
junction - ANSWER ✔ base-to-emitter
31) What are the leads called on a silicon controlled rectifier? -
ANSWER ✔ Anode, gate, cathode
32) Once triggered, a silicon controlled rectifier stays on until -
ANSWER ✔ current flow is interrupted
33) When checking a SCR with an ohmmeter, what must be done
to verify proper triggering operation? - ANSWER ✔ Connect the
negative lead to the cathode and positive lead to the anode and
connect a jumper wire from the gate to the anode and then remove
the jumper.
34) A silicone controlled rectifier is an example of a... -
ANSWER ✔ Discrete electronic component
35) What is normally done to remove ripple voltage from a full
wave rectifier? - ANSWER ✔ Add capacitors and inductors after
the rectifier diodes
36) Zener diodes - ANSWER ✔ connected in reverse biased in a
circuit
37) Characteristic of a Shunt regulator? - ANSWER ✔ If
current through the load increases, current through the zener
decreases
VERSION(2025/2026) FINAL EXAM
QUESTIONS WITH CORRECT
ANSWERS A+ GRADED!!
1) What material should you use to seat brushes? - ANSWER ✔
Sandpaper
2) What color is a good commutator with good commutation? -
ANSWER ✔ Chocolate
3) Most common cause of commutator problems? - ANSWER ✔
Brush pressure too light
4) What is the result when a brush grades are mixed on a
commutator? - ANSWER ✔ The results are unpredictable
5) What is the synchronous speed of a three phase 30Hz 6 pole
motor? - ANSWER ✔ 600 rpm
6) A squirrel cage motor runs clockwise when connected in ACB
phase sequence. What will the motor do when connected in ABC
sequence? - ANSWER ✔ The motor will run in the
counterclockwise rotation.
7) What device is used to prevent starting wye and delta concurrently
- ANSWER ✔ Walking beam
8) What is the percent of slip for a three-phase 60Hz motor that has 6
poles and rotates at 1157RPM? - ANSWER ✔ 3.58%
,9) Synchronous speed - ANSWER ✔ The speed of the stator's
magnetic field on an induction motor
10) AC induction motors... - ANSWER ✔ uses a stator to act as
a rotating field
11) A motor that can run on both AC and DC - ANSWER ✔
Universal Motor
12) Polarized electrolytic capacitors - ANSWER ✔ Voltage
polarity must be correct
13) What happens in a circuit when the capacitor voltage equals
the source voltage? - ANSWER ✔ Current flow stops in the
circuit
14) What happens to capacitors the instant when power is
applied? - ANSWER ✔ Current is maximum
15) If a circuit has a capacitor of 5 microfarads and a source
voltage of 120 volts DC through a resistance of 200K, how long
will it take to fully charge? - ANSWER ✔ 5 seconds
16) If two capacitors in parallel have equal reactance of 40 ohms,
what is the total reactance? - ANSWER ✔ 20 ohms
17) What will be the total capacitance if two 125microfarad
capacitors are in parallel - ANSWER ✔ 250 microfarads
18) What is the unit of inductance? - ANSWER ✔ Henry
,19) What effect does CEMF have in an inductive circuit? -
ANSWER ✔ It is an opposing force to the applied voltage which
resists changes in circuit current
20) At what point is CEMF greatest in an inductive circuit? -
ANSWER ✔ When the rate of change for current is maximum
21) In a 100 volt 60Hz circuit, what is the total reactance with a 4
Henry inductor in the circuit? - ANSWER ✔ 1507 ohms
22) When using a megger to check insulation resistance to
ground, what is an acceptable minimum resistance? - ANSWER ✔
1 M ohm
23) What are the terminal designation of the diode? - ANSWER
✔ Anode and cathode
24) What is the voltage drop across a silicon diode that is forward
biased? - ANSWER ✔ 0.7 volts
25) What type of rectifier uses four diodes to convert the AC to
DC? - ANSWER ✔ Full wave bridge
26) Zener Diodes - ANSWER ✔ Designed to operate in reverse
bias mode
27) Varistors - ANSWER ✔ Used to prevent component
damage from surges
28) What are the common uses of transistors? - ANSWER ✔
Switching and amplification
, 29) The base and emmiter must be ___ biased in an NPN
transistor. - ANSWER ✔ Forward Biased
30) A .7 V drop from ___-__-___ is an indication of a good
junction - ANSWER ✔ base-to-emitter
31) What are the leads called on a silicon controlled rectifier? -
ANSWER ✔ Anode, gate, cathode
32) Once triggered, a silicon controlled rectifier stays on until -
ANSWER ✔ current flow is interrupted
33) When checking a SCR with an ohmmeter, what must be done
to verify proper triggering operation? - ANSWER ✔ Connect the
negative lead to the cathode and positive lead to the anode and
connect a jumper wire from the gate to the anode and then remove
the jumper.
34) A silicone controlled rectifier is an example of a... -
ANSWER ✔ Discrete electronic component
35) What is normally done to remove ripple voltage from a full
wave rectifier? - ANSWER ✔ Add capacitors and inductors after
the rectifier diodes
36) Zener diodes - ANSWER ✔ connected in reverse biased in a
circuit
37) Characteristic of a Shunt regulator? - ANSWER ✔ If
current through the load increases, current through the zener
decreases
