NEC Master Practice Test Exam
Questions Correct Answers New
Update (A Grade)
If two 10-ohm resistors are connected in series, what is the total resistance of these
resistors? - Answer- 20 ohms
In a split-phase motor, how much greater is the starting current when compared to the
full-load current? - Answer- 6 to 8 times
The terminals of a motor can be identified using a battery and a ___ - Answer- voltmeter
A 5-ohm and a 20-ohm resistor are connected in parallel. What is the total resistance of
these two resistors? - Answer- 4 ohms
The normal location to provide overcurrent protection in an electrical circuit is ___ -
Answer- where the conductor receives its supply
Which factor determines the outcome of an electrical shock? - Answer- The amount of
current
Isolated power systems are used to prevent ___ - Answer- power interruption
The speed of a three-phase squirrel cage induction motor is controlled by the frequency
of the applied voltage and ___ - Answer- the number of poles
Where insulating protective equipment may be damaged, it ___ - Answer- requires its
own protection (e.g., leather gauntlets over rubber gloves)
Individual branch circuits are not required for portable X-ray equipment requiring no
more than ___ - Answer- 60A
The type of rubber protective equipment that is made of natural rubber or a vulcanized
synthetic is ___ - Answer- Type 1
Line isolation monitors must have a green signal lamp that glows when the system is
isolated from ground and located ____ - Answer- so it is visible to staff in the
anesthetizing location
Under strict safety guidelines, which of the following should be used to discharge
capacitors before working on de-energized circuits? - Answer- A safety shorting probe
,Which of the following motors is the best installation choice for an application requiring
adjustable speeds? - Answer- Shunt DC
To make sure the voltage is turned off before touching any terminals, use a ___ -
Answer- voltage tester
If you bend from the waist to pick up an object weighing 20 pounds, the amount of
pressure applied to your lower back is ___ - Answer- 200 pounds
In addition to the NEC, the emergency electrical power for hospitals is governed by the
___ - Answer- Joint Commission
OSHA CFR 1910 is the standard for ______. - Answer- general industry
The most common conductors used for light and power installations range from ___ -
Answer- 4/0 to No. 14 AWG
A circuit has a source voltage of 50V and a current of 10A. What is the power in watts? -
Answer- 500
What is the total resistance of a two-wire circuit that spans a distance of 200' each way
if the resistance per 1,000' is 1.21 ohms? - Answer- 0.484 ohm
The primary method of varying the speed on a DC shunt motor is to adjust the voltage
and current on the field winding or the ___ - Answer- armature
The normal beating heart can be upset by an electrical current as small as ___ -
Answer- 75mA
A three-phase induction motor may have ___ - Answer- 2 poles
Which of the following motors provides constant speed from no-load conditions to full-
load conditions? - Answer- Synchronous
If a circuit has 12 amps of current and the resistance is 20 ohms, the applied voltage is
___ - Answer- 240 volts
The power factor of an induction motor at no-load conditions can be as low as ___ -
Answer- 15%
To keep the voltage drop of a 277V circuit to a maximum of 3%, what would be the
maximum allowable voltage drop? - Answer- 8.3V
Which of the following must be considered when determining the size of the conductor
required to connect an electrical load to the source of supply? - Answer- Permissible
voltage drop
,DC injection breaking is used on the ___ - Answer- the stationary windings of AC
motors
According to NEMA definitions, which of the following is a type of open motor? -
Answer- Weather-protected
A polyphase synchronous motor has three stator windings that are ___ - Answer- 120
degrees apart
The value indicated in rpm on the nameplate is the ___ - Answer- rated full-load speed
In a medical facility, receptacles should be mounted ___ - Answer- 24" above the floor
Horsepower is used to rate the ___ - Answer- output capacity of a motor
If a circuit has 48 amps of current and an applied voltage of 240 volts, the resistance is
___ - Answer- 5 ohms
The NEC requires motor disconnecting means be ___ - Answer- within sight of the
controller location
What is the applied voltage if the current in a circuit is 60 amps and the resistance is 10
ohms? - Answer- 600 volts
Which of the following substances is considered a good semiconductor? - Answer-
Silicon
If the resistance of a circuit is 25 ohms and the current is 10 amps, the power in watts is
___ - Answer- 2,500
Which of the following is used to step voltage down to lower levels before it reaches a
home or office? - Answer- Transformer
The stationary magnet of a DC motor is represented by the ___ - Answer- field poles
For a constant-torque load, the horsepower increases and decreases ___ - Answer- in
direct proportion to the speed
Any exposed live parts must be guarded if they are operating at ___ - Answer- 50V or
more between terminals
Which of the following motors is used when the required starting torque is high and
speed control is desirable? - Answer- Compound
, A correction factor must be applied if the ambient temperature is above ___ - Answer-
86 degrees Fahrenheit
Health care facilities are often supplied by two or more distribution points; this is known
as a ____ - Answer- spot network
What must happen before any work may be performed in a confined space? - Answer-
Completion of a hazard review
A delta-connected motor has ___ - Answer- 9 leads
The synchronous speed at which a four-pole, 60Hz induction motor operates is ___ -
Answer- 1,800 rpm
According to NEMA definitions, which of the following is a type of totally enclosed
motor? - Answer- water-cooled
If a conductor has a diameter of 40 mils, what is the diameter in inches? - Answer- 0.04"
A typical constant-torque load would be a ___ - Answer- conveyor
NFPA 70E provides practical guidance in______. - Answer- electrical hazard
assessment
Attachment plugs and receptacles in hazardous locations must be listed for use in ____
- Answer- Class I, Group C locations
Which of the following should have side rails that extend 36 inches above the top
support point? - Answer- Straight ladders
How many amps are there in the current of a circuit if the voltage source is 140V and
the resistance is 2 ohms? - Answer- 70 amps
Installation of X-ray equipment is governed by ____ - Answer- NEC Article 517, Part V
Which of the following is most likely to use dynamic braking? - Answer- Forklift
If five No. 10 AWG current-carrying conductors are installed in a raceway where the
ambient temperature is 70 degrees Fahrenheit, the allowable ampacity must be ___ -
Answer- reduced by 80% of its value
The square mil area of a conductor that is 0.250" on all sides is ____ - Answer- 62,500
square mils
You are required to be evaluated by a physician to ensure that you are physically fit to
use which of the following types of protective equipment? - Answer- Respirator
Questions Correct Answers New
Update (A Grade)
If two 10-ohm resistors are connected in series, what is the total resistance of these
resistors? - Answer- 20 ohms
In a split-phase motor, how much greater is the starting current when compared to the
full-load current? - Answer- 6 to 8 times
The terminals of a motor can be identified using a battery and a ___ - Answer- voltmeter
A 5-ohm and a 20-ohm resistor are connected in parallel. What is the total resistance of
these two resistors? - Answer- 4 ohms
The normal location to provide overcurrent protection in an electrical circuit is ___ -
Answer- where the conductor receives its supply
Which factor determines the outcome of an electrical shock? - Answer- The amount of
current
Isolated power systems are used to prevent ___ - Answer- power interruption
The speed of a three-phase squirrel cage induction motor is controlled by the frequency
of the applied voltage and ___ - Answer- the number of poles
Where insulating protective equipment may be damaged, it ___ - Answer- requires its
own protection (e.g., leather gauntlets over rubber gloves)
Individual branch circuits are not required for portable X-ray equipment requiring no
more than ___ - Answer- 60A
The type of rubber protective equipment that is made of natural rubber or a vulcanized
synthetic is ___ - Answer- Type 1
Line isolation monitors must have a green signal lamp that glows when the system is
isolated from ground and located ____ - Answer- so it is visible to staff in the
anesthetizing location
Under strict safety guidelines, which of the following should be used to discharge
capacitors before working on de-energized circuits? - Answer- A safety shorting probe
,Which of the following motors is the best installation choice for an application requiring
adjustable speeds? - Answer- Shunt DC
To make sure the voltage is turned off before touching any terminals, use a ___ -
Answer- voltage tester
If you bend from the waist to pick up an object weighing 20 pounds, the amount of
pressure applied to your lower back is ___ - Answer- 200 pounds
In addition to the NEC, the emergency electrical power for hospitals is governed by the
___ - Answer- Joint Commission
OSHA CFR 1910 is the standard for ______. - Answer- general industry
The most common conductors used for light and power installations range from ___ -
Answer- 4/0 to No. 14 AWG
A circuit has a source voltage of 50V and a current of 10A. What is the power in watts? -
Answer- 500
What is the total resistance of a two-wire circuit that spans a distance of 200' each way
if the resistance per 1,000' is 1.21 ohms? - Answer- 0.484 ohm
The primary method of varying the speed on a DC shunt motor is to adjust the voltage
and current on the field winding or the ___ - Answer- armature
The normal beating heart can be upset by an electrical current as small as ___ -
Answer- 75mA
A three-phase induction motor may have ___ - Answer- 2 poles
Which of the following motors provides constant speed from no-load conditions to full-
load conditions? - Answer- Synchronous
If a circuit has 12 amps of current and the resistance is 20 ohms, the applied voltage is
___ - Answer- 240 volts
The power factor of an induction motor at no-load conditions can be as low as ___ -
Answer- 15%
To keep the voltage drop of a 277V circuit to a maximum of 3%, what would be the
maximum allowable voltage drop? - Answer- 8.3V
Which of the following must be considered when determining the size of the conductor
required to connect an electrical load to the source of supply? - Answer- Permissible
voltage drop
,DC injection breaking is used on the ___ - Answer- the stationary windings of AC
motors
According to NEMA definitions, which of the following is a type of open motor? -
Answer- Weather-protected
A polyphase synchronous motor has three stator windings that are ___ - Answer- 120
degrees apart
The value indicated in rpm on the nameplate is the ___ - Answer- rated full-load speed
In a medical facility, receptacles should be mounted ___ - Answer- 24" above the floor
Horsepower is used to rate the ___ - Answer- output capacity of a motor
If a circuit has 48 amps of current and an applied voltage of 240 volts, the resistance is
___ - Answer- 5 ohms
The NEC requires motor disconnecting means be ___ - Answer- within sight of the
controller location
What is the applied voltage if the current in a circuit is 60 amps and the resistance is 10
ohms? - Answer- 600 volts
Which of the following substances is considered a good semiconductor? - Answer-
Silicon
If the resistance of a circuit is 25 ohms and the current is 10 amps, the power in watts is
___ - Answer- 2,500
Which of the following is used to step voltage down to lower levels before it reaches a
home or office? - Answer- Transformer
The stationary magnet of a DC motor is represented by the ___ - Answer- field poles
For a constant-torque load, the horsepower increases and decreases ___ - Answer- in
direct proportion to the speed
Any exposed live parts must be guarded if they are operating at ___ - Answer- 50V or
more between terminals
Which of the following motors is used when the required starting torque is high and
speed control is desirable? - Answer- Compound
, A correction factor must be applied if the ambient temperature is above ___ - Answer-
86 degrees Fahrenheit
Health care facilities are often supplied by two or more distribution points; this is known
as a ____ - Answer- spot network
What must happen before any work may be performed in a confined space? - Answer-
Completion of a hazard review
A delta-connected motor has ___ - Answer- 9 leads
The synchronous speed at which a four-pole, 60Hz induction motor operates is ___ -
Answer- 1,800 rpm
According to NEMA definitions, which of the following is a type of totally enclosed
motor? - Answer- water-cooled
If a conductor has a diameter of 40 mils, what is the diameter in inches? - Answer- 0.04"
A typical constant-torque load would be a ___ - Answer- conveyor
NFPA 70E provides practical guidance in______. - Answer- electrical hazard
assessment
Attachment plugs and receptacles in hazardous locations must be listed for use in ____
- Answer- Class I, Group C locations
Which of the following should have side rails that extend 36 inches above the top
support point? - Answer- Straight ladders
How many amps are there in the current of a circuit if the voltage source is 140V and
the resistance is 2 ohms? - Answer- 70 amps
Installation of X-ray equipment is governed by ____ - Answer- NEC Article 517, Part V
Which of the following is most likely to use dynamic braking? - Answer- Forklift
If five No. 10 AWG current-carrying conductors are installed in a raceway where the
ambient temperature is 70 degrees Fahrenheit, the allowable ampacity must be ___ -
Answer- reduced by 80% of its value
The square mil area of a conductor that is 0.250" on all sides is ____ - Answer- 62,500
square mils
You are required to be evaluated by a physician to ensure that you are physically fit to
use which of the following types of protective equipment? - Answer- Respirator
