NEIEP 400 FINAL EXAM VERSION 2 2026/2027 | Latest
Update | Verified Q&A | 100% Correct Grade A | Pass
Guaranteed - A+ Graded
SECTION 1: ELECTRICAL FUNDAMENTALS & METER USAGE (25
Questions)
Q1: A technician measures voltage across a running DC hoist motor armature using a
standard DMM. The meter is set to AC voltage. What is the most likely result?
A. The meter will display the correct DC voltage value
B. The meter will display approximately zero or an erratic low value [CORRECT]
C. The meter will display double the actual DC voltage
D. The meter will display the RMS equivalent of the DC voltage
Correct Answer: B
Rationale: A DMM set to AC voltage mode uses AC coupling or averaging circuits
designed for alternating current; when measuring DC voltage, it will display
approximately zero or an unstable, erratic low reading because the AC detection
circuitry cannot properly process a steady DC potential. The technician must always
verify the meter is set to the correct function (DCV) before taking measurements on DC
circuits to avoid diagnostic errors.
Q2: Counter-electromotive force (CEMF) in a DC motor serves what primary function
during normal operation?
A. It increases armature current during startup
B. It acts as an inherent current limiter as motor speed increases [CORRECT]
C. It eliminates the need for external motor protection
D. It prevents armature reaction from occurring
Correct Answer: B
,Rationale: CEMF is generated by the rotating armature conductors cutting through the
magnetic field, opposing the applied voltage; as motor speed increases, CEMF
increases, thereby reducing the net voltage across the armature and inherently limiting
current draw. This is a fundamental principle of DC motor operation—without CEMF,
armature current would be limited only by conductor resistance and would reach
destructive levels.
Q3: The neutral plane in a DC machine is defined as the position where:
A. The armature conductors are moving parallel to the magnetic flux lines
B. The armature conductors are moving perpendicular to the magnetic flux lines and
CEMF is zero
C. The armature conductors are moving perpendicular to the magnetic flux lines and
CEMF is maximum
D. The armature conductors cut no flux and no voltage is induced in the coil undergoing
commutation [CORRECT]
Correct Answer: D
Rationale: The neutral plane is the position around the commutator where the coil
undergoing commutation is momentarily short-circuited by the brush and should have
zero induced voltage to prevent sparking; at this exact position, the coil sides are
moving parallel to the main flux lines (not cutting flux), resulting in zero induced EMF
and smooth current reversal. Distractor B describes the position of maximum torque
production, not the neutral plane.
Q4: A six-pole AC induction motor is connected to a 60 Hz power supply. What is the
synchronous speed?
A. 900 RPM
B. 1,000 RPM
C. 1,200 RPM [CORRECT]
D. 1,800 RPM
Correct Answer: C
,Rationale: Using the synchronous speed formula Ns = 120 × f / P, where f = 60 Hz and P
= 6 poles: Ns = (120 × 60) / 6 = 7, = 1,200 RPM. This is a fundamental calculation
for elevator motor analysis; distractors represent common math errors (using 4 poles
for 1,800 RPM, 8 poles for 900 RPM, or incorrect formula application).
Q5: A technician needs to measure leakage resistance to ground on a 480V elevator
motor feeder cable. Which instrument is specifically designed and appropriate for this
test?
A. Standard digital multimeter on the 2,000MΩ range
B. Clamp-on ammeter with voltage sensing capability
C. Megger (insulation resistance tester) at 500V or 1,000V DC [CORRECT]
D. Oscilloscope with high-voltage probe
Correct Answer: C
Rationale: A Megger (insulation resistance tester) applies a high DC test voltage
(typically 500V or 1,000V for 480V systems) to measure leakage resistance to ground in
megohms, which is the standard and safe method for evaluating insulation integrity. A
standard DMM cannot generate sufficient test voltage to stress the insulation properly,
and using a DMM may yield falsely high readings that mask insulation degradation.
Q6: When using a clamp-on ammeter to measure current in a motor feeder conductor,
the technician must:
A. Disconnect the conductor and insert the meter in series
B. Break the circuit and bridge the connection with the clamp jaws
C. Clamp the jaws around a single conductor without disconnecting any wires
[CORRECT]
D. Clamp the jaws around all three phase conductors simultaneously for balanced load
measurement
Correct Answer: C
Rationale: The clamp-on ammeter operates on the principle of magnetic induction,
measuring the magnetic field around a single conductor; it requires no circuit
interruption and provides safe, non-invasive current measurement. Clamping all three
, conductors simultaneously would cause the magnetic fields to cancel (in a balanced
system), resulting in a near-zero reading, which is a common technician error.
Q7: An ohmmeter is being used to detect a ground fault in a DC motor armature coil.
The proper procedure requires:
A. Measuring between the commutator segments and the motor frame with all coils
connected
B. Measuring between adjacent commutator segments only
C. Measuring from each commutator segment to the armature shaft or frame, isolating
the component from external circuits [CORRECT]
D. Measuring across the line terminals with the motor running
Correct Answer: C
Rationale: To detect a ground in an armature coil, the ohmmeter must measure
resistance from each commutator segment (which connects to individual coils) to the
metal frame/shaft; the component must be isolated from external circuits to prevent
parallel paths that would mask the fault. Measuring between adjacent segments only
checks coil continuity, not ground insulation.
Q8: Precision shunts are used in conjunction with millivoltmeters to measure:
A. High AC voltage in transformer secondaries
B. High DC current by developing a precise, proportional low millivoltage drop
[CORRECT]
C. Insulation resistance in motor windings
D. Frequency in AC power systems
Correct Answer: B
Rationale: A precision shunt is a low-resistance conductor designed to produce a
specific millivoltage drop (typically 50mV or 100mV) proportional to the high current
passing through it; the millivoltmeter measures this drop, and the current is calculated
using Ohm's Law (I = V/R). This is essential for high-current DC measurements in
elevator drive systems where direct meter insertion would be impractical.
Update | Verified Q&A | 100% Correct Grade A | Pass
Guaranteed - A+ Graded
SECTION 1: ELECTRICAL FUNDAMENTALS & METER USAGE (25
Questions)
Q1: A technician measures voltage across a running DC hoist motor armature using a
standard DMM. The meter is set to AC voltage. What is the most likely result?
A. The meter will display the correct DC voltage value
B. The meter will display approximately zero or an erratic low value [CORRECT]
C. The meter will display double the actual DC voltage
D. The meter will display the RMS equivalent of the DC voltage
Correct Answer: B
Rationale: A DMM set to AC voltage mode uses AC coupling or averaging circuits
designed for alternating current; when measuring DC voltage, it will display
approximately zero or an unstable, erratic low reading because the AC detection
circuitry cannot properly process a steady DC potential. The technician must always
verify the meter is set to the correct function (DCV) before taking measurements on DC
circuits to avoid diagnostic errors.
Q2: Counter-electromotive force (CEMF) in a DC motor serves what primary function
during normal operation?
A. It increases armature current during startup
B. It acts as an inherent current limiter as motor speed increases [CORRECT]
C. It eliminates the need for external motor protection
D. It prevents armature reaction from occurring
Correct Answer: B
,Rationale: CEMF is generated by the rotating armature conductors cutting through the
magnetic field, opposing the applied voltage; as motor speed increases, CEMF
increases, thereby reducing the net voltage across the armature and inherently limiting
current draw. This is a fundamental principle of DC motor operation—without CEMF,
armature current would be limited only by conductor resistance and would reach
destructive levels.
Q3: The neutral plane in a DC machine is defined as the position where:
A. The armature conductors are moving parallel to the magnetic flux lines
B. The armature conductors are moving perpendicular to the magnetic flux lines and
CEMF is zero
C. The armature conductors are moving perpendicular to the magnetic flux lines and
CEMF is maximum
D. The armature conductors cut no flux and no voltage is induced in the coil undergoing
commutation [CORRECT]
Correct Answer: D
Rationale: The neutral plane is the position around the commutator where the coil
undergoing commutation is momentarily short-circuited by the brush and should have
zero induced voltage to prevent sparking; at this exact position, the coil sides are
moving parallel to the main flux lines (not cutting flux), resulting in zero induced EMF
and smooth current reversal. Distractor B describes the position of maximum torque
production, not the neutral plane.
Q4: A six-pole AC induction motor is connected to a 60 Hz power supply. What is the
synchronous speed?
A. 900 RPM
B. 1,000 RPM
C. 1,200 RPM [CORRECT]
D. 1,800 RPM
Correct Answer: C
,Rationale: Using the synchronous speed formula Ns = 120 × f / P, where f = 60 Hz and P
= 6 poles: Ns = (120 × 60) / 6 = 7, = 1,200 RPM. This is a fundamental calculation
for elevator motor analysis; distractors represent common math errors (using 4 poles
for 1,800 RPM, 8 poles for 900 RPM, or incorrect formula application).
Q5: A technician needs to measure leakage resistance to ground on a 480V elevator
motor feeder cable. Which instrument is specifically designed and appropriate for this
test?
A. Standard digital multimeter on the 2,000MΩ range
B. Clamp-on ammeter with voltage sensing capability
C. Megger (insulation resistance tester) at 500V or 1,000V DC [CORRECT]
D. Oscilloscope with high-voltage probe
Correct Answer: C
Rationale: A Megger (insulation resistance tester) applies a high DC test voltage
(typically 500V or 1,000V for 480V systems) to measure leakage resistance to ground in
megohms, which is the standard and safe method for evaluating insulation integrity. A
standard DMM cannot generate sufficient test voltage to stress the insulation properly,
and using a DMM may yield falsely high readings that mask insulation degradation.
Q6: When using a clamp-on ammeter to measure current in a motor feeder conductor,
the technician must:
A. Disconnect the conductor and insert the meter in series
B. Break the circuit and bridge the connection with the clamp jaws
C. Clamp the jaws around a single conductor without disconnecting any wires
[CORRECT]
D. Clamp the jaws around all three phase conductors simultaneously for balanced load
measurement
Correct Answer: C
Rationale: The clamp-on ammeter operates on the principle of magnetic induction,
measuring the magnetic field around a single conductor; it requires no circuit
interruption and provides safe, non-invasive current measurement. Clamping all three
, conductors simultaneously would cause the magnetic fields to cancel (in a balanced
system), resulting in a near-zero reading, which is a common technician error.
Q7: An ohmmeter is being used to detect a ground fault in a DC motor armature coil.
The proper procedure requires:
A. Measuring between the commutator segments and the motor frame with all coils
connected
B. Measuring between adjacent commutator segments only
C. Measuring from each commutator segment to the armature shaft or frame, isolating
the component from external circuits [CORRECT]
D. Measuring across the line terminals with the motor running
Correct Answer: C
Rationale: To detect a ground in an armature coil, the ohmmeter must measure
resistance from each commutator segment (which connects to individual coils) to the
metal frame/shaft; the component must be isolated from external circuits to prevent
parallel paths that would mask the fault. Measuring between adjacent segments only
checks coil continuity, not ground insulation.
Q8: Precision shunts are used in conjunction with millivoltmeters to measure:
A. High AC voltage in transformer secondaries
B. High DC current by developing a precise, proportional low millivoltage drop
[CORRECT]
C. Insulation resistance in motor windings
D. Frequency in AC power systems
Correct Answer: B
Rationale: A precision shunt is a low-resistance conductor designed to produce a
specific millivoltage drop (typically 50mV or 100mV) proportional to the high current
passing through it; the millivoltmeter measures this drop, and the current is calculated
using Ohm's Law (I = V/R). This is essential for high-current DC measurements in
elevator drive systems where direct meter insertion would be impractical.
