NEIEP 400 Final Review Questions With Accurate Solutions.
Which is true when placing an ammeter into a circuit ? - accurate answers-The
meter is placed in series with any component
Which of the following describes the most useful feature of the clamp - on
ammeter ? - accurate answers-Does not require that connections be disturbed
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 ? - accurate answers-Capacitor
What must be done when testing a resistance to avoid false readings caused
by parallel circuit paths ? - accurate answers-Remove one of the two wires to
the item being tested
A minus sign in front of a reading of the digital voltmeter indicates which of
the following ? - accurate answers-The positive lead is connected to the
negative source
Which of the following statements best describes CEMF ? - accurate answers-
Opposes the applied voltage .
Refer to the figure . What will be the phase relationship between the primary
and secondary voltages ? - accurate answers-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 ? - accurate answers-
Isolation transformer
What is the power available from a 68 kVA transformer connected in open
delta configuration ? - accurate answers-39.44 kVA
The secondary winding of an 11,000 volt to 220 volt transformer has 50
windings on the secondary How many turns are on the primary winding ? -
accurate answers-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 ? - accurate answers-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 ? - accurate answers-375 amps
Which statement best describes eddy currents ? - accurate answers-They are
circulating currents set up by magnetic induction .
With the following values : Ep = 208 VAC ; Es = 35 VAC ; Ip = 3.8 amps ; Is =
21.42 amps , what is the efficiency of this transformer ? - accurate answers-95
%
Which of the following would describe a transformer with a fixed voltage
transformation ratio of 1:12 ? - accurate answers-Step - up transformer
Which of the following would describe a transformer with a primary current
of 27 amps and a secondary current of 1 amp ? - accurate answers-Step -
down transformer
Which statement is correct regarding transformers? - accurate answers-The
primary winding terminals are identified with the letter H
Refer to the figure . What type of transformer is represented ? - accurate
answers-Core type with a wye primary and delta secondary
Which would you do to check for an open primary winding ? - accurate
answers-Measure the resistance across the primary
Which statement applies when a secondary winding is completely shorted ? -
accurate answers-Current through the primary is high
Which statement applies when a secondary winding is partially shorted ? -
accurate answers-Current through the secondary is low
Which statement applies when a secondary winding is open ? - accurate
answers-The secondary resistance will be infinity
Which is true when placing an ammeter into a circuit ? - accurate answers-The
meter is placed in series with any component
Which of the following describes the most useful feature of the clamp - on
ammeter ? - accurate answers-Does not require that connections be disturbed
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 ? - accurate answers-Capacitor
What must be done when testing a resistance to avoid false readings caused
by parallel circuit paths ? - accurate answers-Remove one of the two wires to
the item being tested
A minus sign in front of a reading of the digital voltmeter indicates which of
the following ? - accurate answers-The positive lead is connected to the
negative source
Which of the following statements best describes CEMF ? - accurate answers-
Opposes the applied voltage .
Refer to the figure . What will be the phase relationship between the primary
and secondary voltages ? - accurate answers-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 ? - accurate answers-
Isolation transformer
What is the power available from a 68 kVA transformer connected in open
delta configuration ? - accurate answers-39.44 kVA
The secondary winding of an 11,000 volt to 220 volt transformer has 50
windings on the secondary How many turns are on the primary winding ? -
accurate answers-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 ? - accurate answers-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 ? - accurate answers-375 amps
Which statement best describes eddy currents ? - accurate answers-They are
circulating currents set up by magnetic induction .
With the following values : Ep = 208 VAC ; Es = 35 VAC ; Ip = 3.8 amps ; Is =
21.42 amps , what is the efficiency of this transformer ? - accurate answers-95
%
Which of the following would describe a transformer with a fixed voltage
transformation ratio of 1:12 ? - accurate answers-Step - up transformer
Which of the following would describe a transformer with a primary current
of 27 amps and a secondary current of 1 amp ? - accurate answers-Step -
down transformer
Which statement is correct regarding transformers? - accurate answers-The
primary winding terminals are identified with the letter H
Refer to the figure . What type of transformer is represented ? - accurate
answers-Core type with a wye primary and delta secondary
Which would you do to check for an open primary winding ? - accurate
answers-Measure the resistance across the primary
Which statement applies when a secondary winding is completely shorted ? -
accurate answers-Current through the primary is high
Which statement applies when a secondary winding is partially shorted ? -
accurate answers-Current through the secondary is low
Which statement applies when a secondary winding is open ? - accurate
answers-The secondary resistance will be infinity
