NEIEP 400 FINAL EXAM NEWEST ACTUAL EXAM QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+
Question 1
Which is true when placing an ammeter into a circuit?
A) The meter is placed in parallel with the load
B) The meter is placed in series with any component
C) The meter must be placed across the power source
D) The meter should be used only when power is off
E) The meter must be calibrated to the total resistance of the circuit
Correct Answer: B) The meter is placed in series with any component
Rationale: An ammeter measures the flow of current (amperes). To measure the full flow of
current through a circuit or a specific component, the meter must be part of the current
path, which requires a series connection.
Question 2
Which of the following describes the most useful feature of the clamp-on ammeter?
A) It measures higher voltage than standard meters
B) It can measure resistance without a battery
C) It does not require that connections be disturbed
D) It provides a more accurate reading than a digital meter
E) It can be used as a voltmeter simultaneously
Correct Answer: C) Does not require that connections be disturbed
Rationale: Unlike standard ammeters that require "breaking" the circuit to insert the leads
in series, a clamp-on ammeter uses the principle of induction to measure the magnetic field
around a wire. This allows the technician to take readings without disconnecting any wires.
Question 3
Which of the following devices is an example of a reactive component that can store energy for
long periods of time, causing an electrical hazard even with power removed?
A) Resistor
B) Inductor
C) Transformer
D) Capacitor
E) Rheostat
Correct Answer: D) Capacitor
Rationale: Capacitors store electrical energy in an electrostatic field. Depending on their
size and the circuit design, they can retain a high-voltage charge long after the main power
supply has been disconnected, posing a significant shock hazard.
Question 4
What must be done when testing resistance to avoid false readings caused by parallel circuit
paths?
A) Increase the voltage of the ohmmeter
, 2
B) Remove one of the two wires to the item being tested
C) Short out the power supply
D) Test the component while it is energized
E) Use a clamp-on ammeter instead
Correct Answer: B) Remove one of the two wires to the item being tested
Rationale: If a component is tested for resistance while still fully connected to a circuit, the
ohmmeter may measure the resistance of other connected components (parallel paths),
leading to an inaccurately low reading. Disconnecting at least one lead isolates the
component.
Question 5
A minus sign in front of a reading on a digital voltmeter indicates which of the following?
A) The battery in the meter is low
B) The circuit has a short to ground
C) The positive lead is connected to the negative source
D) The voltage is AC instead of DC
E) The meter is in the resistance mode
Correct Answer: C) The positive lead is connected to the negative source
Rationale: In DC voltage measurements, digital meters are polarity-sensitive. If the red
(positive) lead is touched to a point of lower potential than the black (negative) lead, the
meter will display a negative sign to indicate reversed polarity.
Question 6
Which of the following statements best describes Counter-Electromotive Force (CEMF)?
A) It increases the applied voltage
B) It is produced only in resistors
C) It opposes the applied voltage
D) It is the primary cause of eddy currents
E) It is measured in Ohms
Correct Answer: C) Opposes the applied voltage.
Rationale: CEMF is an induced voltage that occurs in an electric motor's armature as it
rotates through a magnetic field. According to Lenz's Law, this induced voltage acts in the
opposite direction of the voltage being applied to the motor.
Question 7
Refer to the figure (standard transformer phase relationship). What will be the phase relationship
between the primary and secondary voltages?
A) They will be in phase
B) The secondary voltage will be 90° out of phase
C) The secondary voltage will be 180° out of phase
D) The secondary voltage will lead by 45°
, 3
E) The secondary voltage will be DC
Correct Answer: C) The secondary voltage will be 180° out of phase.
Rationale: In many standard transformer configurations, particularly those where the
windings are wound in opposite directions, the induced secondary voltage is 180 degrees
out of phase with the primary voltage.
Question 8
Which type of transformer would be used to prevent noise from being fed back to the line
without changing the voltage levels?
A) Step-up transformer
B) Step-down transformer
C) Auto-transformer
D) Isolation transformer
E) Current transformer
Correct Answer: D) Isolation transformer
Rationale: An isolation transformer typically has a 1:1 ratio. Its primary purpose is to
physically and electrically separate two circuits to prevent electrical noise and provide
safety, without altering the magnitude of the voltage.
Question 9
What is the power available from a 68 kVA transformer connected in an open delta
configuration?
A) 68 kVA
B) 34 kVA
C) 39.44 kVA
D) 58.82 kVA
E) 117.8 kVA
Correct Answer: C) 39.44 kVA
Rationale: When a three-phase delta transformer bank is operated in "open delta" (one
transformer removed), the capacity of the bank is reduced to 58% of the original capacity.
Calculation: 68 kVA x 0.58 = 39.44 kVA.
Question 10
The secondary winding of an 11,000 volt to 220 volt transformer has 50 turns. How many turns
are on the primary winding?
A) 110 turns
B) 500 turns
C) 1,100 turns
D) 2,500 turns
E) 5,000 turns
Correct Answer: D) 2500 turns
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+
Question 1
Which is true when placing an ammeter into a circuit?
A) The meter is placed in parallel with the load
B) The meter is placed in series with any component
C) The meter must be placed across the power source
D) The meter should be used only when power is off
E) The meter must be calibrated to the total resistance of the circuit
Correct Answer: B) The meter is placed in series with any component
Rationale: An ammeter measures the flow of current (amperes). To measure the full flow of
current through a circuit or a specific component, the meter must be part of the current
path, which requires a series connection.
Question 2
Which of the following describes the most useful feature of the clamp-on ammeter?
A) It measures higher voltage than standard meters
B) It can measure resistance without a battery
C) It does not require that connections be disturbed
D) It provides a more accurate reading than a digital meter
E) It can be used as a voltmeter simultaneously
Correct Answer: C) Does not require that connections be disturbed
Rationale: Unlike standard ammeters that require "breaking" the circuit to insert the leads
in series, a clamp-on ammeter uses the principle of induction to measure the magnetic field
around a wire. This allows the technician to take readings without disconnecting any wires.
Question 3
Which of the following devices is an example of a reactive component that can store energy for
long periods of time, causing an electrical hazard even with power removed?
A) Resistor
B) Inductor
C) Transformer
D) Capacitor
E) Rheostat
Correct Answer: D) Capacitor
Rationale: Capacitors store electrical energy in an electrostatic field. Depending on their
size and the circuit design, they can retain a high-voltage charge long after the main power
supply has been disconnected, posing a significant shock hazard.
Question 4
What must be done when testing resistance to avoid false readings caused by parallel circuit
paths?
A) Increase the voltage of the ohmmeter
, 2
B) Remove one of the two wires to the item being tested
C) Short out the power supply
D) Test the component while it is energized
E) Use a clamp-on ammeter instead
Correct Answer: B) Remove one of the two wires to the item being tested
Rationale: If a component is tested for resistance while still fully connected to a circuit, the
ohmmeter may measure the resistance of other connected components (parallel paths),
leading to an inaccurately low reading. Disconnecting at least one lead isolates the
component.
Question 5
A minus sign in front of a reading on a digital voltmeter indicates which of the following?
A) The battery in the meter is low
B) The circuit has a short to ground
C) The positive lead is connected to the negative source
D) The voltage is AC instead of DC
E) The meter is in the resistance mode
Correct Answer: C) The positive lead is connected to the negative source
Rationale: In DC voltage measurements, digital meters are polarity-sensitive. If the red
(positive) lead is touched to a point of lower potential than the black (negative) lead, the
meter will display a negative sign to indicate reversed polarity.
Question 6
Which of the following statements best describes Counter-Electromotive Force (CEMF)?
A) It increases the applied voltage
B) It is produced only in resistors
C) It opposes the applied voltage
D) It is the primary cause of eddy currents
E) It is measured in Ohms
Correct Answer: C) Opposes the applied voltage.
Rationale: CEMF is an induced voltage that occurs in an electric motor's armature as it
rotates through a magnetic field. According to Lenz's Law, this induced voltage acts in the
opposite direction of the voltage being applied to the motor.
Question 7
Refer to the figure (standard transformer phase relationship). What will be the phase relationship
between the primary and secondary voltages?
A) They will be in phase
B) The secondary voltage will be 90° out of phase
C) The secondary voltage will be 180° out of phase
D) The secondary voltage will lead by 45°
, 3
E) The secondary voltage will be DC
Correct Answer: C) The secondary voltage will be 180° out of phase.
Rationale: In many standard transformer configurations, particularly those where the
windings are wound in opposite directions, the induced secondary voltage is 180 degrees
out of phase with the primary voltage.
Question 8
Which type of transformer would be used to prevent noise from being fed back to the line
without changing the voltage levels?
A) Step-up transformer
B) Step-down transformer
C) Auto-transformer
D) Isolation transformer
E) Current transformer
Correct Answer: D) Isolation transformer
Rationale: An isolation transformer typically has a 1:1 ratio. Its primary purpose is to
physically and electrically separate two circuits to prevent electrical noise and provide
safety, without altering the magnitude of the voltage.
Question 9
What is the power available from a 68 kVA transformer connected in an open delta
configuration?
A) 68 kVA
B) 34 kVA
C) 39.44 kVA
D) 58.82 kVA
E) 117.8 kVA
Correct Answer: C) 39.44 kVA
Rationale: When a three-phase delta transformer bank is operated in "open delta" (one
transformer removed), the capacity of the bank is reduced to 58% of the original capacity.
Calculation: 68 kVA x 0.58 = 39.44 kVA.
Question 10
The secondary winding of an 11,000 volt to 220 volt transformer has 50 turns. How many turns
are on the primary winding?
A) 110 turns
B) 500 turns
C) 1,100 turns
D) 2,500 turns
E) 5,000 turns
Correct Answer: D) 2500 turns
