NEC Master practice test 100%
Accurate!!
If two 10-ohm resistors are connected in series, what is the total resistance of these resistors? -
ANSWER20 ohms
In a split-phase motor, how much greater is the starting current when compared to the full-load
current? - ANSWER6 to 8 times
The terminals of a motor can be identified using a battery and a ___ - ANSWERvoltmeter
A 5-ohm and a 20-ohm resistor are connected in parallel. What is the total resistance of these two
resistors? - ANSWER4 ohms
The normal location to provide overcurrent protection in an electrical circuit is ___ - ANSWERwhere
the conductor receives its supply
Which factor determines the outcome of an electrical shock? - ANSWERThe amount of current
Isolated power systems are used to prevent ___ - ANSWERpower interruption
The speed of a three-phase squirrel cage induction motor is controlled by the frequency of the
applied voltage and ___ - ANSWERthe number of poles
Where insulating protective equipment may be damaged, it ___ - ANSWERrequires 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 ___ -
ANSWER60A
The type of rubber protective equipment that is made of natural rubber or a vulcanized synthetic is
___ - ANSWERType 1
Line isolation monitors must have a green signal lamp that glows when the system is isolated from
ground and located ____ - ANSWERso 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? - ANSWERA safety shorting probe
Which of the following motors is the best installation choice for an application requiring adjustable
speeds? - ANSWERShunt DC
To make sure the voltage is turned off before touching any terminals, use a ___ - ANSWERvoltage
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 ___ - ANSWER200 pounds
In addition to the NEC, the emergency electrical power for hospitals is governed by the ___ -
ANSWERJoint Commission
,OSHA CFR 1910 is the standard for ______. - ANSWERgeneral industry
The most common conductors used for light and power installations range from ___ - ANSWER4/0 to
No. 14 AWG
A circuit has a source voltage of 50V and a current of 10A. What is the power in watts? - ANSWER500
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? - ANSWER0.484 ohm
The NEC requires motor disconnecting means be ___ - ANSWERwithin 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? -
ANSWER600 volts
Which of the following substances is considered a good semiconductor? - ANSWERSilicon
If the resistance of a circuit is 25 ohms and the current is 10 amps, the power in watts is ___ -
ANSWER2,500
Which of the following is used to step voltage down to lower levels before it reaches a home or
office? - ANSWERTransformer
The stationary magnet of a DC motor is represented by the ___ - ANSWERfield poles
For a constant-torque load, the horsepower increases and decreases ___ - ANSWERin direct
proportion to the speed
Any exposed live parts must be guarded if they are operating at ___ - ANSWER50V or more between
terminals
Which of the following motors is used when the required starting torque is high and speed control is
desirable? - ANSWERCompound
A correction factor must be applied if the ambient temperature is above ___ - ANSWER86 degrees
Fahrenheit
Health care facilities are often supplied by two or more distribution points; this is known as a ____ -
ANSWERspot network
What must happen before any work may be performed in a confined space? - ANSWERCompletion of
a hazard review
A delta-connected motor has ___ - ANSWER9 leads
The synchronous speed at which a four-pole, 60Hz induction motor operates is ___ - ANSWER1,800
rpm
According to NEMA definitions, which of the following is a type of totally enclosed motor? -
ANSWERwater-cooled
If a conductor has a diameter of 40 mils, what is the diameter in inches? - ANSWER0.04"
A typical constant-torque load would be a ___ - ANSWERconveyor
NFPA 70E provides practical guidance in______. - ANSWERelectrical hazard assessment
,Attachment plugs and receptacles in hazardous locations must be listed for use in ____ -
ANSWERClass I, Group C locations
Which of the following should have side rails that extend 36 inches above the top support point? -
ANSWERStraight ladders
How many amps are there in the current of a circuit if the voltage source is 140V and the resistance
is 2 ohms? - ANSWER70 amps
Installation of X-ray equipment is governed by ____ - ANSWERNEC Article 517, Part V
Which of the following is most likely to use dynamic braking? - ANSWERForklift
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 ___ - ANSWERreduced by
80% of its value
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 ___ - ANSWERarmature
The normal beating heart can be upset by an electrical current as small as ___ - ANSWER75mA
A three-phase induction motor may have ___ - ANSWER2 poles
Which of the following motors provides constant speed from no-load conditions to full-load
conditions? - ANSWERSynchronous
If a circuit has 12 amps of current and the resistance is 20 ohms, the applied voltage is ___ -
ANSWER240 volts
The power factor of an induction motor at no-load conditions can be as low as ___ - ANSWER15%
To keep the voltage drop of a 277V circuit to a maximum of 3%, what would be the maximum
allowable voltage drop? - ANSWER8.3V
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? - ANSWERPermissible voltage drop
DC injection breaking is used on the ___ - ANSWERthe stationary windings of AC motors
According to NEMA definitions, which of the following is a type of open motor? - ANSWERWeather-
protected
A polyphase synchronous motor has three stator windings that are ___ - ANSWER120 degrees apart
The value indicated in rpm on the nameplate is the ___ - ANSWERrated full-load speed
In a medical facility, receptacles should be mounted ___ - ANSWER24" above the floor
Horsepower is used to rate the ___ - ANSWERoutput capacity of a motor
If a circuit has 48 amps of current and an applied voltage of 240 volts, the resistance is ___ -
ANSWER5 ohms
The square mil area of a conductor that is 0.250" on all sides is ____ - ANSWER62,500 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? - ANSWERRespirator
Low voltage equipment that is typically in contact with patients must be moisture-resistant and
operate on ___ - ANSWER10V or less
Which of the following is true with regard to working near cranes? - ANSWEROnly individuals trained
in rigging should ever rig material for a lift.
Which of the following battery byproducts can be explosive when mixed with air? -
ANSWERHydrogen
Operating rooms must be provided with a minimum of ___ - ANSWER36 receptacles
Insulating gloves must be inspected by the user ______. - ANSWERbefore each use
Which motor should be used for applications that require frequent starts without overheating the
motor? - ANSWERWound rotor induction motor
In a parallel circuit, the voltage drop ___ - ANSWERis the same across all loads
When a guardrail cannot be attached to a building, a solution may be to install a ______. -
ANSWERcontrolled access zone
A No. 1 isolated conductor must be identified using which of the following colors? - ANSWEROrange
Health care facilities that do NOT require a Type 1 or Type 2 EES may use batteries for emergency
power provided that they maintain 87-1/2 percent of their voltage under full load for a period of ___
- ANSWER90 minutes
What color is reserved for identifying the high leg of a three-phase, four-wire system? -
ANSWEROrange
Power to low-voltage equipment must be supplied from an ___ - ANSWERindividual portable
isolation transformer
In a DC series motor, how much of its full-load torque is developed at starting? - ANSWER500%
A live-dead-live test is conducted in order to ___ - ANSWERverify that a circuit is de-energized
Which of the following is the threshold at which a power source is considered high voltage in the
context of safety? - ANSWER600V
The most common service factor appearing on a motor's nameplate is ___ - ANSWER1.15
In a health care facility, a television is an example of a ___ - ANSWERnonessential load
For a given number of poles, which of the following determines the speed of an AC motor? -
ANSWERFrequency
Any facility that admits patients on electrical life support equipment must have a ___ - ANSWERType
1 EES
Hospital-grade receptacles are ___ - ANSWERtested for superior mechanical strength
An acceptable method of identifying grounded conductors larger than No. 6 AWG is by tagging them
or marking them ____ - ANSWERWhite
Accurate!!
If two 10-ohm resistors are connected in series, what is the total resistance of these resistors? -
ANSWER20 ohms
In a split-phase motor, how much greater is the starting current when compared to the full-load
current? - ANSWER6 to 8 times
The terminals of a motor can be identified using a battery and a ___ - ANSWERvoltmeter
A 5-ohm and a 20-ohm resistor are connected in parallel. What is the total resistance of these two
resistors? - ANSWER4 ohms
The normal location to provide overcurrent protection in an electrical circuit is ___ - ANSWERwhere
the conductor receives its supply
Which factor determines the outcome of an electrical shock? - ANSWERThe amount of current
Isolated power systems are used to prevent ___ - ANSWERpower interruption
The speed of a three-phase squirrel cage induction motor is controlled by the frequency of the
applied voltage and ___ - ANSWERthe number of poles
Where insulating protective equipment may be damaged, it ___ - ANSWERrequires 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 ___ -
ANSWER60A
The type of rubber protective equipment that is made of natural rubber or a vulcanized synthetic is
___ - ANSWERType 1
Line isolation monitors must have a green signal lamp that glows when the system is isolated from
ground and located ____ - ANSWERso 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? - ANSWERA safety shorting probe
Which of the following motors is the best installation choice for an application requiring adjustable
speeds? - ANSWERShunt DC
To make sure the voltage is turned off before touching any terminals, use a ___ - ANSWERvoltage
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 ___ - ANSWER200 pounds
In addition to the NEC, the emergency electrical power for hospitals is governed by the ___ -
ANSWERJoint Commission
,OSHA CFR 1910 is the standard for ______. - ANSWERgeneral industry
The most common conductors used for light and power installations range from ___ - ANSWER4/0 to
No. 14 AWG
A circuit has a source voltage of 50V and a current of 10A. What is the power in watts? - ANSWER500
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? - ANSWER0.484 ohm
The NEC requires motor disconnecting means be ___ - ANSWERwithin 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? -
ANSWER600 volts
Which of the following substances is considered a good semiconductor? - ANSWERSilicon
If the resistance of a circuit is 25 ohms and the current is 10 amps, the power in watts is ___ -
ANSWER2,500
Which of the following is used to step voltage down to lower levels before it reaches a home or
office? - ANSWERTransformer
The stationary magnet of a DC motor is represented by the ___ - ANSWERfield poles
For a constant-torque load, the horsepower increases and decreases ___ - ANSWERin direct
proportion to the speed
Any exposed live parts must be guarded if they are operating at ___ - ANSWER50V or more between
terminals
Which of the following motors is used when the required starting torque is high and speed control is
desirable? - ANSWERCompound
A correction factor must be applied if the ambient temperature is above ___ - ANSWER86 degrees
Fahrenheit
Health care facilities are often supplied by two or more distribution points; this is known as a ____ -
ANSWERspot network
What must happen before any work may be performed in a confined space? - ANSWERCompletion of
a hazard review
A delta-connected motor has ___ - ANSWER9 leads
The synchronous speed at which a four-pole, 60Hz induction motor operates is ___ - ANSWER1,800
rpm
According to NEMA definitions, which of the following is a type of totally enclosed motor? -
ANSWERwater-cooled
If a conductor has a diameter of 40 mils, what is the diameter in inches? - ANSWER0.04"
A typical constant-torque load would be a ___ - ANSWERconveyor
NFPA 70E provides practical guidance in______. - ANSWERelectrical hazard assessment
,Attachment plugs and receptacles in hazardous locations must be listed for use in ____ -
ANSWERClass I, Group C locations
Which of the following should have side rails that extend 36 inches above the top support point? -
ANSWERStraight ladders
How many amps are there in the current of a circuit if the voltage source is 140V and the resistance
is 2 ohms? - ANSWER70 amps
Installation of X-ray equipment is governed by ____ - ANSWERNEC Article 517, Part V
Which of the following is most likely to use dynamic braking? - ANSWERForklift
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 ___ - ANSWERreduced by
80% of its value
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 ___ - ANSWERarmature
The normal beating heart can be upset by an electrical current as small as ___ - ANSWER75mA
A three-phase induction motor may have ___ - ANSWER2 poles
Which of the following motors provides constant speed from no-load conditions to full-load
conditions? - ANSWERSynchronous
If a circuit has 12 amps of current and the resistance is 20 ohms, the applied voltage is ___ -
ANSWER240 volts
The power factor of an induction motor at no-load conditions can be as low as ___ - ANSWER15%
To keep the voltage drop of a 277V circuit to a maximum of 3%, what would be the maximum
allowable voltage drop? - ANSWER8.3V
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? - ANSWERPermissible voltage drop
DC injection breaking is used on the ___ - ANSWERthe stationary windings of AC motors
According to NEMA definitions, which of the following is a type of open motor? - ANSWERWeather-
protected
A polyphase synchronous motor has three stator windings that are ___ - ANSWER120 degrees apart
The value indicated in rpm on the nameplate is the ___ - ANSWERrated full-load speed
In a medical facility, receptacles should be mounted ___ - ANSWER24" above the floor
Horsepower is used to rate the ___ - ANSWERoutput capacity of a motor
If a circuit has 48 amps of current and an applied voltage of 240 volts, the resistance is ___ -
ANSWER5 ohms
The square mil area of a conductor that is 0.250" on all sides is ____ - ANSWER62,500 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? - ANSWERRespirator
Low voltage equipment that is typically in contact with patients must be moisture-resistant and
operate on ___ - ANSWER10V or less
Which of the following is true with regard to working near cranes? - ANSWEROnly individuals trained
in rigging should ever rig material for a lift.
Which of the following battery byproducts can be explosive when mixed with air? -
ANSWERHydrogen
Operating rooms must be provided with a minimum of ___ - ANSWER36 receptacles
Insulating gloves must be inspected by the user ______. - ANSWERbefore each use
Which motor should be used for applications that require frequent starts without overheating the
motor? - ANSWERWound rotor induction motor
In a parallel circuit, the voltage drop ___ - ANSWERis the same across all loads
When a guardrail cannot be attached to a building, a solution may be to install a ______. -
ANSWERcontrolled access zone
A No. 1 isolated conductor must be identified using which of the following colors? - ANSWEROrange
Health care facilities that do NOT require a Type 1 or Type 2 EES may use batteries for emergency
power provided that they maintain 87-1/2 percent of their voltage under full load for a period of ___
- ANSWER90 minutes
What color is reserved for identifying the high leg of a three-phase, four-wire system? -
ANSWEROrange
Power to low-voltage equipment must be supplied from an ___ - ANSWERindividual portable
isolation transformer
In a DC series motor, how much of its full-load torque is developed at starting? - ANSWER500%
A live-dead-live test is conducted in order to ___ - ANSWERverify that a circuit is de-energized
Which of the following is the threshold at which a power source is considered high voltage in the
context of safety? - ANSWER600V
The most common service factor appearing on a motor's nameplate is ___ - ANSWER1.15
In a health care facility, a television is an example of a ___ - ANSWERnonessential load
For a given number of poles, which of the following determines the speed of an AC motor? -
ANSWERFrequency
Any facility that admits patients on electrical life support equipment must have a ___ - ANSWERType
1 EES
Hospital-grade receptacles are ___ - ANSWERtested for superior mechanical strength
An acceptable method of identifying grounded conductors larger than No. 6 AWG is by tagging them
or marking them ____ - ANSWERWhite
