NEIEP 400 LATEST QUESTIONS WITH VERIFIED ANSWERS -
UPDATED 2026
When placing an ammeter into a circuit, what is true? The meter is placed in
series with any component.
What is the most useful feature of the clamp-on ammeter? Does not require
that connections be disturbed.
Which device is an example of a reactive component that can store energy
for long periods causing an electrical hazard even with power removed?
Capacitor.
What must be done when testing a resistance to avoid false readings caused
by parallel circuit paths? Remove one of the two wires to the item being
tested.
What does a minus sign in front of a reading on a digital voltmeter
indicate? The positive lead is connected to the negative source.
What best describes CEMF? Opposes the applied voltage.
What will be the phase relationship between the primary and secondary
voltages in a transformer? The secondary voltage will be 180° out of phase.
Which type of transformer would be used to prevent noise from being fed
back to the line without changing the voltage levels? Isolation transformer.
What is the power available from a 68 kVA transformer connected in open
delta configuration? 39.44 kVA.
How many turns are on the primary winding of an 11,000 volt to 220 volt
transformer that has 50 windings on the secondary? 2500 turns.
, A transformer has 728 turns on the primary winding and 56 turns on the
secondary. With 120 volts applied on the primary, what is the output
voltage on the secondary? 9.23 volts.
A transformer has a primary voltage of 440 V with 100 turns and a 15:1
voltage ratio of transformation. With a primary current of 25 amps, what
is the current in the secondary? 375 amps.
What best describes eddy currents? They are circulating currents set up by
magnetic induction.
With Ep = 208 VAC, Es = 35 VAC, Ip = 3.8 amps, Is = 21.42 amps, what is
the efficiency of this transformer? 95%.
What would describe a transformer with a fixed voltage transformation
ratio of 1:12? Step-up transformer.
What would describe a transformer with a primary current of 27 amps and
a secondary current of 1 amp? Step-down transformer.
Which statement is correct regarding transformers? The primary winding
terminals are identified with the letter H.
What type of transformer has a wye primary and delta secondary? Core
type with a wye primary and delta secondary.
How would you check for an open primary winding? Measure the resistance
across the primary.
What happens when a secondary winding is completely shorted? Current
through the primary is high.
What happens when a secondary winding is partially shorted? Current
through the secondary is low.
What happens when a secondary winding is open? The secondary resistance
will be infinity.
How can the direction of the magnetic field around a wire when electron
current flows through it be determined? The Left-Hand Rule.
What is the direction of electron current flow? Negative to positive.
What is the output of an elementary generator called? Alternating current.
UPDATED 2026
When placing an ammeter into a circuit, what is true? The meter is placed in
series with any component.
What is the most useful feature of the clamp-on ammeter? Does not require
that connections be disturbed.
Which device is an example of a reactive component that can store energy
for long periods causing an electrical hazard even with power removed?
Capacitor.
What must be done when testing a resistance to avoid false readings caused
by parallel circuit paths? Remove one of the two wires to the item being
tested.
What does a minus sign in front of a reading on a digital voltmeter
indicate? The positive lead is connected to the negative source.
What best describes CEMF? Opposes the applied voltage.
What will be the phase relationship between the primary and secondary
voltages in a transformer? The secondary voltage will be 180° out of phase.
Which type of transformer would be used to prevent noise from being fed
back to the line without changing the voltage levels? Isolation transformer.
What is the power available from a 68 kVA transformer connected in open
delta configuration? 39.44 kVA.
How many turns are on the primary winding of an 11,000 volt to 220 volt
transformer that has 50 windings on the secondary? 2500 turns.
, A transformer has 728 turns on the primary winding and 56 turns on the
secondary. With 120 volts applied on the primary, what is the output
voltage on the secondary? 9.23 volts.
A transformer has a primary voltage of 440 V with 100 turns and a 15:1
voltage ratio of transformation. With a primary current of 25 amps, what
is the current in the secondary? 375 amps.
What best describes eddy currents? They are circulating currents set up by
magnetic induction.
With Ep = 208 VAC, Es = 35 VAC, Ip = 3.8 amps, Is = 21.42 amps, what is
the efficiency of this transformer? 95%.
What would describe a transformer with a fixed voltage transformation
ratio of 1:12? Step-up transformer.
What would describe a transformer with a primary current of 27 amps and
a secondary current of 1 amp? Step-down transformer.
Which statement is correct regarding transformers? The primary winding
terminals are identified with the letter H.
What type of transformer has a wye primary and delta secondary? Core
type with a wye primary and delta secondary.
How would you check for an open primary winding? Measure the resistance
across the primary.
What happens when a secondary winding is completely shorted? Current
through the primary is high.
What happens when a secondary winding is partially shorted? Current
through the secondary is low.
What happens when a secondary winding is open? The secondary resistance
will be infinity.
How can the direction of the magnetic field around a wire when electron
current flows through it be determined? The Left-Hand Rule.
What is the direction of electron current flow? Negative to positive.
What is the output of an elementary generator called? Alternating current.
